kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree

Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory")
deprecated KBUILD_SRCTREE.

It is only used in tools/testing/selftest/ to distinguish out-of-tree
build. Replace it with a new boolean flag, building_out_of_srctree.

I also replaced the conditional ($(srctree),.) because the next commit
will allow an absolute path to be used for $(srctree) even when building
in the source tree.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index 99336b60f1a4..91ad737ff538 100644
--- a/Makefile
+++ b/Makefile
@@ -228,9 +228,12 @@ ifeq ("$(origin M)", "command line")
   KBUILD_EXTMOD := $(M)
 endif
 
+export KBUILD_CHECKSRC KBUILD_EXTMOD
+
 ifeq ($(abs_srctree),$(abs_objtree))
         # building in the source tree
         srctree := .
+        building_out_of_srctree :=
 else
         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
                 # building in a subdirectory of the source tree
@@ -238,19 +241,13 @@ else
         else
                 srctree := $(abs_srctree)
         endif
-
-        # TODO:
-        # KBUILD_SRC is only used to distinguish in-tree/out-of-tree build.
-        # Replace it with $(srctree) or something.
-        KBUILD_SRC := $(abs_srctree)
+        building_out_of_srctree := 1
 endif
 
-export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
-
 objtree         := .
 VPATH           := $(srctree)
 
-export srctree objtree VPATH
+export building_out_of_srctree srctree objtree VPATH
 
 # To make sure we do not include .config for any of the *config targets
 # catch them early, and hand them over to scripts/kconfig/Makefile
@@ -453,7 +450,7 @@ USERINCLUDE    := \
 LINUXINCLUDE    := \
                 -I$(srctree)/arch/$(SRCARCH)/include \
                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
-                $(if $(filter .,$(srctree)),,-I$(srctree)/include) \
+                $(if $(building_out_of_srctree),-I$(srctree)/include) \
                 -I$(objtree)/include \
                 $(USERINCLUDE)
 
@@ -514,7 +511,7 @@ PHONY += outputmakefile
 # At the same time when output Makefile generated, generate .gitignore to
 # ignore whole output directory
 outputmakefile:
-ifneq ($(srctree),.)
+ifdef building_out_of_srctree
         $(Q)ln -fsn $(srctree) source
         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
         $(Q)test -e .gitignore || \
@@ -1101,7 +1098,7 @@ PHONY += prepare archprepare prepare1 prepare3
 # and if so do:
 # 1) Check that make has not been executed in the kernel src $(srctree)
 prepare3: include/config/kernel.release
-ifneq ($(srctree),.)
+ifdef building_out_of_srctree
         @$(kecho) '  Using $(srctree) as source for kernel'
         $(Q)if [ -f $(srctree)/.config -o \
                  -d $(srctree)/include/config -o \