On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote: > The makefile.prog is added only, will be used in sample/bpf/Makefile > later in order to switch cross-compiling on CC from HOSTCC. > > 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.prog 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. So this is really Makefile.host or Makefile.user, right? In BPF, 'prog' can refers to user prog or bpf prog. To avoid ambiguity, maybe Makefile.host? > > Makefile.prog contains only stuff needed for samples/bpf, potentially > can be reused and extended for other prog sets later and now needed What do you mean 'extended for other prog sets'? I am wondering whether we could just include 'scripts/Makefile.host'? How hard it is? > only for unblocking tricky samples/bpf cross compilation. > > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> > --- > samples/bpf/Makefile.prog | 77 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 77 insertions(+) > create mode 100644 samples/bpf/Makefile.prog > > diff --git a/samples/bpf/Makefile.prog b/samples/bpf/Makefile.prog > new file mode 100644 > index 000000000000..3781999b9193 > --- /dev/null > +++ b/samples/bpf/Makefile.prog > @@ -0,0 +1,77 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# ========================================================================== > +# Building binaries on the host system > +# Binaries are not used during the compilation of the kernel, and intendent > +# to be build for target board, target board can be host ofc. Added to build > +# binaries to run not on host system. > +# > +# Only C is supported, but can be extended for C++. The above comment is not needed. samples/bpf/ only have C now. I am wondering whether your below scripts can be simplified, e.g., removing cxxobjs. > +# > +# Sample syntax (see Documentation/kbuild/makefiles.rst for reference) > +# progs-y := xsk_example > +# Will compile xdpsock_example.c and create an executable named xsk_example > +# > +# progs-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 > +# > +__progs := $(sort $(progs-y)) > + > +# C code > +# Executables compiled from a single .c file > +prog-csingle := $(foreach m,$(__progs), \ > + $(if $($(m)-objs)$($(m)-cxxobjs),,$(m))) > + > +# C executables linked based on several .o files > +prog-cmulti := $(foreach m,$(__progs),\ > + $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m)))) > + > +# Object (.o) files compiled from .c files > +prog-cobjs := $(sort $(foreach m,$(__progs),$($(m)-objs))) > + > +prog-csingle := $(addprefix $(obj)/,$(prog-csingle)) > +prog-cmulti := $(addprefix $(obj)/,$(prog-cmulti)) > +prog-cobjs := $(addprefix $(obj)/,$(prog-cobjs)) > + > +##### > +# Handle options to gcc. Support building with separate output directory > + > +_progc_flags = $(PROGS_CFLAGS) \ > + $(PROGCFLAGS_$(basetarget).o) > + > +# $(objtree)/$(obj) for including generated headers from checkin source files > +ifeq ($(KBUILD_EXTMOD),) > +ifdef building_out_of_srctree > +_progc_flags += -I $(objtree)/$(obj) > +endif > +endif > + > +progc_flags = -Wp,-MD,$(depfile) $(_progc_flags) > + > +# Create executable from a single .c file > +# prog-csingle -> Executable > +quiet_cmd_prog-csingle = CC $@ > + cmd_prog-csingle = $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ $< \ > + $(PROGS_LDLIBS) $(PROGLDLIBS_$(@F)) > +$(prog-csingle): $(obj)/%: $(src)/%.c FORCE > + $(call if_changed_dep,prog-csingle) > + > +# Link an executable based on list of .o files, all plain c > +# prog-cmulti -> executable > +quiet_cmd_prog-cmulti = LD $@ > + cmd_prog-cmulti = $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ \ > + $(addprefix $(obj)/,$($(@F)-objs)) \ > + $(PROGS_LDLIBS) $(PROGLDLIBS_$(@F)) > +$(prog-cmulti): $(prog-cobjs) FORCE > + $(call if_changed,prog-cmulti) > +$(call multi_depend, $(prog-cmulti), , -objs) > + > +# Create .o file from a single .c file > +# prog-cobjs -> .o > +quiet_cmd_prog-cobjs = CC $@ > + cmd_prog-cobjs = $(CC) $(progc_flags) -c -o $@ $< > +$(prog-cobjs): $(obj)/%.o: $(src)/%.c FORCE > + $(call if_changed_dep,prog-cobjs) >
