On Wed, Sep 18, 2019 at 3:12 AM Ivan Khoronzhuk <ivan.khoronz...@linaro.org> wrote: > > On Tue, Sep 17, 2019 at 04:19:40PM -0700, Andrii Nakryiko wrote: > >On Mon, Sep 16, 2019 at 3:58 AM Ivan Khoronzhuk > ><ivan.khoronz...@linaro.org> wrote: > >> > >> The makefile.target is added only and will be used in > > > >typo: Makefile > > > >> sample/bpf/Makefile later in order to switch cross-compiling on CC > > > >on -> to > > > >> from HOSTCC environment. > >> > >> The HOSTCC is supposed to build binaries and tools running on the host > >> afterwards, in order to simplify build or so, like "fixdep" or else. > >> In case of cross compiling "fixdep" is executed on host when the rest > >> samples should run on target arch. In order to build binaries for > >> target arch with CC and tools running on host with HOSTCC, lets add > >> Makefile.target for simplicity, having definition and routines similar > >> to ones, used in script/Makefile.host. This allows later add > >> cross-compilation to samples/bpf with minimum changes. > >> > >> The tprog stands for target programs built with CC. > > > >Why tprog? Could we just use prog: hostprog vs prog. > Prev. version was with prog, but Yonghong Song found it ambiguous. > As prog can be bpf also. So, decision was made to follow logic: > * target prog - non bpf progs > * bpf prog = bpf prog, that can be later smth similar, providing build options > for each bpf object separately. >
Well, I'm not going to insist, but BPF program is a C function, compiled BPF .o file is BPF object, so I don't think there is going to be too much confusion to have progs and hostprogs in Makefile. But I'm fine with tprog. > Details here: > https://lkml.org/lkml/2019/9/13/1037 > > > > >> > >> Makefile.target contains only stuff needed for samples/bpf, potentially > >> can be reused later and now needed only for unblocking tricky > >> samples/bpf cross compilation. > >> > >> Signed-off-by: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > >> --- > >> samples/bpf/Makefile.target | 75 +++++++++++++++++++++++++++++++++++++ > >> 1 file changed, 75 insertions(+) > >> create mode 100644 samples/bpf/Makefile.target > >> > >> diff --git a/samples/bpf/Makefile.target b/samples/bpf/Makefile.target > >> new file mode 100644 > >> index 000000000000..fb6de63f7d2f > >> --- /dev/null > >> +++ b/samples/bpf/Makefile.target > >> @@ -0,0 +1,75 @@ > >> +# SPDX-License-Identifier: GPL-2.0 > >> +# > >> ========================================================================== > >> +# Building binaries on the host system > >> +# Binaries are not used during the compilation of the kernel, and > >> intendent > > > >typo: intended > > > >> +# to be build for target board, target board can be host ofc. Added to > >> build > > > >What's ofc, is it "of course"? > yes, ofc ) Alright, let's not try to save 5 letters, it's quite confusing. > > > > >> +# binaries to run not on host system. > >> +# > >> +# Sample syntax (see Documentation/kbuild/makefiles.rst for reference) > >> +# tprogs-y := xsk_example > >> +# Will compile xdpsock_example.c and create an executable named > >> xsk_example > > > >You mix references to xsk_example and xdpsock_example, which is very > >confusing. I'm guessing you meant to use xdpsock_example consistently. > Oh, yes. Thanks. > > > > >> +# > >> +# tprogs-y := xdpsock > >> +# xdpsock-objs := xdpsock_1.o xdpsock_2.o > >> +# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable > >> +# xdpsock, based on xdpsock_1.o and xdpsock_2.o > >> +# > >> +# Inherited from scripts/Makefile.host > > > >"Inspired by" or "Derived from" would be probably more appropriate term :) > I will replace with "Derived from", looks better. > sounds good > > > >> +# > >> +__tprogs := $(sort $(tprogs-y)) > >> + > >> +# C code > >> +# Executables compiled from a single .c file > >> +tprog-csingle := $(foreach m,$(__tprogs), \ > >> + $(if $($(m)-objs),,$(m))) > >> + > >> +# C executables linked based on several .o files > >> +tprog-cmulti := $(foreach m,$(__tprogs),\ > >> + $(if $($(m)-objs),$(m))) > >> + > >> +# Object (.o) files compiled from .c files > >> +tprog-cobjs := $(sort $(foreach m,$(__tprogs),$($(m)-objs))) > >> + > >> +tprog-csingle := $(addprefix $(obj)/,$(tprog-csingle)) > >> +tprog-cmulti := $(addprefix $(obj)/,$(tprog-cmulti)) > >> +tprog-cobjs := $(addprefix $(obj)/,$(tprog-cobjs)) > >> + > >> +##### > >> +# Handle options to gcc. Support building with separate output directory > >> + > >> +_tprogc_flags = $(TPROGS_CFLAGS) \ > >> + $(TPROGCFLAGS_$(basetarget).o) > >> + > >> +# $(objtree)/$(obj) for including generated headers from checkin source > >> files > >> +ifeq ($(KBUILD_EXTMOD),) > >> +ifdef building_out_of_srctree > >> +_tprogc_flags += -I $(objtree)/$(obj) > >> +endif > >> +endif > >> + > >> +tprogc_flags = -Wp,-MD,$(depfile) $(_tprogc_flags) > >> + > >> +# Create executable from a single .c file > >> +# tprog-csingle -> Executable > >> +quiet_cmd_tprog-csingle = CC $@ > >> + cmd_tprog-csingle = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) > >> -o $@ $< \ > >> + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) > >> +$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE > >> + $(call if_changed_dep,tprog-csingle) > >> + > >> +# Link an executable based on list of .o files, all plain c > >> +# tprog-cmulti -> executable > >> +quiet_cmd_tprog-cmulti = LD $@ > >> + cmd_tprog-cmulti = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \ > >> + $(addprefix $(obj)/,$($(@F)-objs)) \ > >> + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) > >> +$(tprog-cmulti): $(tprog-cobjs) FORCE > >> + $(call if_changed,tprog-cmulti) > >> +$(call multi_depend, $(tprog-cmulti), , -objs) > >> + > >> +# Create .o file from a single .c file > >> +# tprog-cobjs -> .o > >> +quiet_cmd_tprog-cobjs = CC $@ > >> + cmd_tprog-cobjs = $(CC) $(tprogc_flags) -c -o $@ $< > >> +$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE > >> + $(call if_changed_dep,tprog-cobjs) > >> -- > >> 2.17.1 > >> > > > >tprogs is quite confusing, but overall looks good to me. > I tend to leave it as tprogs, unless it's going to be progs and agreed with > Yonghong. > > It follows logic: > - tprogs for bins > - bpfprogs or bojs or bprogs (could be) for bpf obj as mentioned above, we never build "BPF programs", they are always part of BPF objects. But as I mentioned, I'm fine with sticking to tprog. > > -- > Regards, > Ivan Khoronzhuk
