The conditional: ifneq ($(hostprogs),) ... is evaluated to true if $(hostprogs) does not contain any word but whitespace characters. ifneq ($(strip $(hostprogs)),) ... is a safe way to avoid interpreting whitespace as a non-empty value, but I'd rather want to use the side-effect of $(sort ...) to do the equivalent. $(sort ...) is used in scripts/Makefile.host in order to drop duplication in $(hostprogs). It is also useful to strip excessive spaces. Move $(sort ...) before evaluating the ifneq. Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- scripts/Makefile.build | 5 ++++- scripts/Makefile.host | 10 ++++------ 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d41c1cd453b9..e0b6b5db11c2 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -45,12 +45,15 @@ include $(kbuild-file) include scripts/Makefile.lib -# Do not include hostprogs rules unless needed +# Do not include hostprogs rules unless needed. +# $(sort ...) is used here to remove duplicated words and excessive spaces. +hostprogs := $(sort $(hostprogs)) ifneq ($(hostprogs),) include scripts/Makefile.host endif # Do not include userprogs rules unless needed. +# $(sort ...) is used here to remove duplicated words and excessive spaces. userprogs := $(sort $(userprogs)) ifneq ($(userprogs),) include scripts/Makefile.userprogs diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 687ca3f309e9..278b4d6ac945 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -38,24 +38,22 @@ $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE # Will compile qconf as a C++ program, and menu as a C program. # They are linked as C++ code to the executable qconf -__hostprogs := $(sort $(hostprogs)) - # C code # Executables compiled from a single .c file -host-csingle := $(foreach m,$(__hostprogs), \ +host-csingle := $(foreach m,$(hostprogs), \ $(if $($(m)-objs)$($(m)-cxxobjs),,$(m))) # C executables linked based on several .o files -host-cmulti := $(foreach m,$(__hostprogs),\ +host-cmulti := $(foreach m,$(hostprogs),\ $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m)))) # Object (.o) files compiled from .c files -host-cobjs := $(sort $(foreach m,$(__hostprogs),$($(m)-objs))) +host-cobjs := $(sort $(foreach m,$(hostprogs),$($(m)-objs))) # C++ code # C++ executables compiled from at least one .cc file # and zero or more .c files -host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m))) +host-cxxmulti := $(foreach m,$(hostprogs),$(if $($(m)-cxxobjs),$(m))) # C++ Object (.o) files compiled from .cc files host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs))) -- 2.25.1
