From 688931a5ad4e55ba0c215248ba510cd67bc3afb4 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 19 Mar 2019 13:02:36 +0900 Subject: [PATCH] kbuild: skip sub-make for in-tree build with GNU Make 4.x Commit 2b50f7ab6368 ("kbuild: add workaround for Debian make-kpkg") annoyed people who want to wrap the top Makefile with GNUmakefile to customize it for their use. On second thought, we do not need to run the sub-make for in-tree build with Make 4.x because the 'MAKEFLAGS += -rR' issue only happens on GNU Make 3.x. With this commit, people will get back their workflow, and the Debian make-kpkg will still work. Fixes: 2b50f7ab6368 ("kbuild: add workaround for Debian make-kpkg") Reported-by: Andreas Schwab Reported-by: David Howells Signed-off-by: Masahiro Yamada Tested-by: Andreas Schwab Tested-by: David Howells --- Makefile | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/Makefile b/Makefile index 8c6acfdfe660..6c0635f69982 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 ($(sub-make-done),1) # Do not use make's built-in rules and variables # (this increases performance and avoids hard-to-debug behaviour) MAKEFLAGS += -rR -# 'MAKEFLAGS += -rR' does not become immediately effective for old -# GNU Make versions. Cancel implicit rules for this Makefile. -$(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 +147,16 @@ 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 $(MAKEFILE_LIST)): ; +endif + +ifeq ($(need-sub-make),1) + PHONY += $(MAKECMDGOALS) sub-make $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make @@ -171,8 +168,11 @@ sub-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 @@ -1757,7 +1757,7 @@ 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: -- 2.11.0