kbuild: sort hostprogs before passing it to ifneq

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@kernel.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index d54adf0dcf39..a467b9323442 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