linux/scripts/genksyms/Makefile
Masahiro Yamada faabed295c kbuild: introduce hostprogs-always-y and userprogs-always-y
To build host programs, you need to add the program names to 'hostprogs'
to use the necessary build rule, but it is not enough to build them
because there is no dependency.

There are two types of host programs: built as the prerequisite of
another (e.g. gen_crc32table in lib/Makefile), or always built when
Kbuild visits the Makefile (e.g. genksyms in scripts/genksyms/Makefile).

The latter is typical in Makefiles under scripts/, which contains host
programs globally used during the kernel build. To build them, you need
to add them to both 'hostprogs' and 'always-y'.

This commit adds hostprogs-always-y as a shorthand.

The same applies to user programs. net/bpfilter/Makefile builds
bpfilter_umh on demand, hence always-y is unneeded. In contrast,
programs under samples/ are added to both 'userprogs' and 'always-y'
so they are always built when Kbuild visits the Makefiles.

userprogs-always-y works as a shorthand.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2020-08-10 01:32:59 +09:00

31 lines
934 B
Makefile

# SPDX-License-Identifier: GPL-2.0
hostprogs-always-y += genksyms
genksyms-objs := genksyms.o parse.tab.o lex.lex.o
# FIXME: fix the ambiguous grammar in parse.y and delete this hack
#
# Suppress shift/reduce, reduce/reduce conflicts warnings
# unless W=1 is specified.
#
# Just in case, run "$(YACC) --version" without suppressing stderr
# so that 'bison: not found' will be displayed if it is missing.
ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
quiet_cmd_bison_no_warn = $(quiet_cmd_bison)
cmd_bison_no_warn = $(YACC) --version >/dev/null; \
$(cmd_bison) 2>/dev/null
$(obj)/pars%.tab.c $(obj)/pars%.tab.h: $(src)/pars%.y FORCE
$(call if_changed,bison_no_warn)
endif
# -I needed for generated C source (shipped source)
HOSTCFLAGS_parse.tab.o := -I $(srctree)/$(src)
HOSTCFLAGS_lex.lex.o := -I $(srctree)/$(src)
# dependencies on generated files need to be listed explicitly
$(obj)/lex.lex.o: $(obj)/parse.tab.h