haproxy/include/make/options.mk
Willy Tarreau d78c346670 BUILD: makefile: support USE_xxx=0 as well
William rightfully reported that not supporting =0 to disable a USE_xxx
option is sometimes painful (e.g. a script might do USE_xxx=$(command)).
It's not that difficult to handle actually, we just need to consider the
value 0 as empty at the few places that test for an empty string in
options.mk, and in each "ifneq" test in the main Makefile, so let's do
that. We even take care of preserving the original value in the build
options string so that building with USE_OPENSSL=0 will be reported
as-is in haproxy -vv, and with "-OPENSSL" in the feature list.
2024-04-11 11:06:19 +02:00

66 lines
3.4 KiB
Makefile

# this contains various functions and macros used to manipulate USE_* options
# and their flags
# Depending on the target platform, some options are set, as well as some
# CFLAGS and LDFLAGS. All variables pre-set here will not appear in the build
# options string. They may be set to any value, but are historically set to
# "implicit" which eases debugging. You should not have to change anything
# there unless you're adding support for a new platform.
default_opts = $(foreach name,$(1),$(eval $(name)=implicit))
# Return USE_xxx=$(USE_xxx) if the variable was set from the environment or the
# command line.
ignore_implicit = $(if $(subst environment,,$(origin $(1))), \
$(if $(subst command line,,$(origin $(1))),, \
$(1)=$($(1))), \
$(1)=$($(1))) \
# This macro collects all USE_* values except those set to "implicit". This
# is used to report a list of all flags which were used to build this version.
# Do not assign anything to it.
build_options = $(foreach opt,$(use_opts),$(call ignore_implicit,$(opt)))
# Make a list of all known features with +/- prepended depending on their
# activation status. Must be a macro so that dynamically enabled ones are
# evaluated with their current status.
build_features = $(foreach opt,$(patsubst USE_%,%,$(sort $(use_opts))),$(if $(USE_$(opt):0=),+$(opt),-$(opt)))
# This returns a list of -DUSE_* for all known USE_* that are set to anything
# neither empty nor '0'.
opts_as_defines = $(foreach opt,$(use_opts),$(if $($(opt):0=),-D$(opt),))
# Lists all enabled or disabled options without the "USE_" prefix
enabled_opts = $(foreach opt,$(patsubst USE_%,%,$(use_opts)),$(if $(USE_$(opt):0=),$(opt),))
disabled_opts = $(foreach opt,$(patsubst USE_%,%,$(use_opts)),$(if $(USE_$(opt):0=),,$(opt)))
# preset all XXX_{INC,LIB,CFLAGS,LDFLAGS,SRC} variables to empty for $1=XXX
reset_opt_vars = $(foreach name,INC LIB CFLAGS LDFLAGS SRC,$(eval $(1)_$(name)=))
# preset all variables for all supported build options among use_opts
reset_opts_vars = $(foreach opt,$(patsubst USE_%,%,$(use_opts)),$(call reset_opt_vars,$(opt)))
# append $(1)_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS if not empty
define collect_opt_flags
ifneq ($$($(1)_CFLAGS),)
OPTIONS_CFLAGS += $$($(1)_CFLAGS)
endif
ifneq ($$($(1)_LDFLAGS),)
OPTIONS_LDFLAGS += $$($(1)_LDFLAGS)
endif
endef
# collect all enabled USE_foo's foo_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS
collect_opts_flags = $(foreach opt,$(enabled_opts),$(eval $(call collect_opt_flags,$(opt))))
# Check that any USE_* variable that was forced actually exist. For this we'll
# build a list of the MAKEOVERRIDES variables that start with USE_*, and keep
# the ones that do not match any of the patterns built by appending '=%' to all
# use_opts. The outstanding ones are thus unknown and each of them produces a
# warning.
warn_unknown_options = \
$(foreach unknown, \
$(filter-out $(foreach opt,$(use_opts),$(opt:==%)), \
$(foreach opt,$(MAKEOVERRIDES), \
$(strip $(filter USE_%,$(opt))))), \
$(warning Warning: ignoring unknown build option: $(unknown)))