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-rw-r--r--Makefile43
1 files changed, 23 insertions, 20 deletions
diff --git a/Makefile b/Makefile
index eef3d3f87c3b..52f067eadc48 100644
--- a/Makefile
+++ b/Makefile
@@ -31,26 +31,12 @@ _all:
# descending is started. They are now explicitly listed as the
# prepare rule.
-# Ugly workaround for Debian make-kpkg:
-# make-kpkg directly includes the top Makefile of Linux kernel. In such a case,
-# skip sub-make to support debian_* targets in ruleset/kernel_version.mk, but
-# displays warning to discourage such abusage.
-ifneq ($(word 2, $(MAKEFILE_LIST)),)
-$(warning Do not include top Makefile of Linux Kernel)
-sub-make-done := 1
-MAKEFLAGS += -rR
-endif
-
-ifneq ($(sub-make-done),1)
+ifneq ($(sub_make_done),1)
# Do not use make's built-in rules and variables
# (this increases performance and avoids hard-to-debug behaviour)
MAKEFLAGS += -rR
-# 'MAKEFLAGS += -rR' does not become immediately effective for old
-# GNU Make versions. Cancel implicit rules for this Makefile.
-$(lastword $(MAKEFILE_LIST)): ;
-
# Avoid funny character set dependencies
unexport LC_ALL
LC_COLLATE=C
@@ -153,6 +139,7 @@ $(if $(KBUILD_OUTPUT),, \
# 'sub-make' below.
MAKEFLAGS += --include-dir=$(CURDIR)
+need-sub-make := 1
else
# Do not print "Entering directory ..." at all for in-tree build.
@@ -160,6 +147,18 @@ MAKEFLAGS += --no-print-directory
endif # ifneq ($(KBUILD_OUTPUT),)
+ifneq ($(filter 3.%,$(MAKE_VERSION)),)
+# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
+# We need to invoke sub-make to avoid implicit rules in the top Makefile.
+need-sub-make := 1
+# Cancel implicit rules for this Makefile.
+$(lastword $(MAKEFILE_LIST)): ;
+endif
+
+export sub_make_done := 1
+
+ifeq ($(need-sub-make),1)
+
PHONY += $(MAKECMDGOALS) sub-make
$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
@@ -167,12 +166,15 @@ $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
# Invoke a second make in the output directory, passing relevant variables
sub-make:
- $(Q)$(MAKE) sub-make-done=1 \
+ $(Q)$(MAKE) \
$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
-else # sub-make-done
+endif # need-sub-make
+endif # sub_make_done
+
# We process the rest of the Makefile if this is the final invocation of make
+ifeq ($(need-sub-make),)
# Do not print "Entering directory ...",
# but we want to display it when entering to the output directory
@@ -497,7 +499,8 @@ outputmakefile:
ifneq ($(KBUILD_SRC),)
$(Q)ln -fsn $(srctree) source
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
- $(Q){ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
+ $(Q)test -e .gitignore || \
+ { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
endif
ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
@@ -677,7 +680,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
+KBUILD_CFLAGS += -Os
else
KBUILD_CFLAGS += -O2
endif
@@ -1759,7 +1762,7 @@ existing-targets := $(wildcard $(sort $(targets)))
endif # ifeq ($(config-targets),1)
endif # ifeq ($(mixed-targets),1)
-endif # sub-make-done
+endif # need-sub-make
PHONY += FORCE
FORCE: