[PATCH 1/6] kbuild: pass $(MAKECMDGOALS) to sub-make as is

[PATCH 1/6] kbuild: pass $(MAKECMDGOALS) to sub-make as is

[Masahiro Yamada]

Manipulating $(MAKECMDGOALS) for sub-make seems odd to me.

[1] 'make O=foo sub-make' is turned into 'make O=foo', which builds
the default targets. It would make sense to terminate the build with:

  *** No rule to make target 'sub-make'.  Stop.

[2] 'make O=foo defconfig _all' is turned into 'make O=foo defconfig',
which changes the behavior.

Let's pass $(MAKECMDGOALS) as is.

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

 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 92ad066..9cbd367 100644
--- a/Makefile
+++ b/Makefile
@@ -168,7 +168,7 @@ $(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all:
 sub-make:
 	$(Q)$(MAKE) \
 	$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
-	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
+	-f $(CURDIR)/Makefile $(MAKECMDGOALS)
 
 endif # need-sub-make
 endif # sub_make_done
-- 
2.7.4

[PATCH 2/6] kbuild: allow Kbuild to start from any directory

[Masahiro Yamada]

Kbuild always runs in the top of the output directory.

If Make starts in the source directory with O=, it relocates the
working directory to the location specified by O=.

Also, users can start build from the output directory by using the
Makefile generated by scripts/mkmakefile.

With a little more effort, Kbuild will be able to start from any
directory path.

This commit allows to specify the source directory by using
the -f option.

For example, you can do:

  $ cd path/to/output/dir
  $ make -f path/to/source/dir/Makefile

Or, for the equivalent behavior, you can do:

  $ make O=path/to/output/dir -f path/to/source/dir/Makefile

KBUILD_SRC is now deprecated.

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

 Makefile | 87 +++++++++++++++++++++++++++++++++++++---------------------------
 1 file changed, 50 insertions(+), 37 deletions(-)

diff --git a/Makefile b/Makefile
index 9cbd367..1b2a70e 100644
--- a/Makefile
+++ b/Makefile
@@ -96,56 +96,65 @@ endif
 
 export quiet Q KBUILD_VERBOSE
 
-# kbuild supports saving output files in a separate directory.
-# To locate output files in a separate directory two syntaxes are supported.
-# In both cases the working directory must be the root of the kernel src.
+# Kbuild will save output files in the current working directory.
+# This does not need to match to the root of the kernel source tree.
+#
+# For example, you can do this:
+#
+#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
+#
+# If you want to save output files in a different location, there are
+# two syntaxes to specify it.
+#
 # 1) O=
 # Use "make O=dir/to/store/output/files/"
 #
 # 2) Set KBUILD_OUTPUT
-# Set the environment variable KBUILD_OUTPUT to point to the directory
-# where the output files shall be placed.
-# export KBUILD_OUTPUT=dir/to/store/output/files/
-# make
+# Set the environment variable KBUILD_OUTPUT to point to the output directory.
+# export KBUILD_OUTPUT=dir/to/store/output/files/; make
 #
 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 # variable.
 
-# KBUILD_SRC is not intended to be used by the regular user (for now),
-# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
-
-# OK, Make called in directory where kernel src resides
-# Do we want to locate output files in a separate directory?
+# Do we want to change the working directory?
 ifeq ("$(origin O)", "command line")
   KBUILD_OUTPUT := $(O)
 endif
 
-ifneq ($(words $(subst :, ,$(CURDIR))), 1)
-  $(error main directory cannot contain spaces nor colons)
+ifneq ($(KBUILD_OUTPUT),)
+# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
+# expand a shell special character '~'. We use a bit tredious way to handle it.
+abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
+$(if $(abs_objtree),, \
+     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
+
+# $(realpath ...) resolves symlinks
+abs_objtree := $(realpath $(abs_objtree))
+else
+abs_objtree := $(CURDIR)
+endif # ifneq ($(KBUILD_OUTPUT),)
+
+ifeq ($(abs_objtree),$(CURDIR))
+# Suppress "Entering directory ..." unless we are changing the work directory.
+MAKEFLAGS += --no-print-directory
+else
+need-sub-make := 1
 endif
 
-ifneq ($(KBUILD_OUTPUT),)
-# check that the output directory actually exists
-saved-output := $(KBUILD_OUTPUT)
-KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
-								&& pwd)
-$(if $(KBUILD_OUTPUT),, \
-     $(error failed to create output directory "$(saved-output)"))
+abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
+
+ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
+$(error source directory cannot contain spaces or colons)
+endif
 
+ifneq ($(abs_srctree),$(abs_objtree))
 # Look for make include files relative to root of kernel src
 #
 # This does not become effective immediately because MAKEFLAGS is re-parsed
-# once after the Makefile is read.  It is OK since we are going to invoke
-# 'sub-make' below.
-MAKEFLAGS += --include-dir=$(CURDIR)
-
+# once after the Makefile is read. We need to invoke sub-make.
+MAKEFLAGS += --include-dir=$(abs_srctree)
 need-sub-make := 1
-else
-
-# Do not print "Entering directory ..." at all for in-tree build.
-MAKEFLAGS += --no-print-directory
-
-endif # ifneq ($(KBUILD_OUTPUT),)
+endif
 
 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
@@ -155,6 +164,7 @@ need-sub-make := 1
 $(lastword $(MAKEFILE_LIST)): ;
 endif
 
+export abs_srctree abs_objtree
 export sub_make_done := 1
 
 ifeq ($(need-sub-make),1)
@@ -166,9 +176,7 @@ $(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all:
 
 # Invoke a second make in the output directory, passing relevant variables
 sub-make:
-	$(Q)$(MAKE) \
-	$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
-	-f $(CURDIR)/Makefile $(MAKECMDGOALS)
+	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 
 endif # need-sub-make
 endif # sub_make_done
@@ -213,16 +221,21 @@ ifeq ("$(origin M)", "command line")
   KBUILD_EXTMOD := $(M)
 endif
 
-ifeq ($(KBUILD_SRC),)
+ifeq ($(abs_srctree),$(abs_objtree))
         # building in the source tree
         srctree := .
 else
-        ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
+        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
                 # building in a subdirectory of the source tree
                 srctree := ..
         else
-                srctree := $(KBUILD_SRC)
+                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)
 endif
 
 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
-- 
2.7.4

[PATCH 3/6] kbuild: mkmakefile: do not check the generated Makefile marker

[Masahiro Yamada]

This hunk was added to avoid accidental overwrite of the top Makefile
in case O= points to the top of the source tree.

As commit 4f1127e20437 ("kbuild: fix infinite make recursion"),
it caused some troubles in the past because Kbuild assumes O=
as out-of-tree build, while it actually works in the source tree.

Now this works more properly; if O= points to the source directory,
it is handled as in-tree build. So, this sanity check is unneeded.

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

 scripts/mkmakefile | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/scripts/mkmakefile b/scripts/mkmakefile
index 412f13f..31de468 100755
--- a/scripts/mkmakefile
+++ b/scripts/mkmakefile
@@ -7,12 +7,6 @@
 # Usage
 # $1 - Kernel src directory
 
-# Only overwrite automatically generated Makefiles
-# (so we do not overwrite kernel Makefile)
-if test -e Makefile && ! grep -q Automatically Makefile
-then
-	exit 0
-fi
 if [ "${quiet}" != "silent_" ]; then
 	echo "  GEN     Makefile"
 fi
-- 
2.7.4

[PATCH 4/6] kbuild: mkmakefile: generate a simple wrapper of top Makefile

[Masahiro Yamada]

Now that Kbuild is able to start from any directory, the generated
Makefile can simply wrap the top Makefile.

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

 scripts/mkmakefile | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/scripts/mkmakefile b/scripts/mkmakefile
index 31de468..4d0faeb 100755
--- a/scripts/mkmakefile
+++ b/scripts/mkmakefile
@@ -12,22 +12,6 @@ if [ "${quiet}" != "silent_" ]; then
 fi
 
 cat << EOF > Makefile
-# Automatically generated by $0: don't edit
-
-ifeq ("\$(origin V)", "command line")
-VERBOSE := \$(V)
-endif
-ifneq (\$(VERBOSE),1)
-Q := @
-endif
-
-MAKEFLAGS += --no-print-directory
-
-.PHONY: __sub-make \$(MAKECMDGOALS)
-
-__sub-make:
-	\$(Q)\$(MAKE) -C $1 O=\$(CURDIR) \$(MAKECMDGOALS)
-
-\$(filter-out __sub-make, \$(MAKECMDGOALS)): __sub-make
-	@:
+# Automatically generated by $(realpath $0): don't edit
+include $(realpath $1/Makefile)
 EOF
-- 
2.7.4

[PATCH 5/6] kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build

[Masahiro Yamada]

KBUILD_SRC was conventionally used for some different purposes:
 [1] To remember the source tree path
 [2] As a flag to check if sub-make is already done
 [3] As a flag to check if Kbuild runs out of tree

For [1], we do not need to remember it because the top Makefile
can compute it by $(realpath $(dir $(lastword $(MAKEFILE_LIST))))

[2] has been replaced with self-commenting 'sub_make_done'.

For [3], we can distinguish in-tree/out-of-tree by comparing
$(srctree) and '.'

This commit converts [3] to prepare for the KBUILD_SRC removal.

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

 Makefile                    | 6 +++---
 scripts/Makefile.build      | 2 +-
 scripts/Makefile.host       | 2 +-
 scripts/Makefile.lib        | 2 +-
 scripts/Makefile.modbuiltin | 2 +-
 scripts/gdb/linux/Makefile  | 2 +-
 scripts/tags.sh             | 2 +-
 7 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 1b2a70e..fa441ca 100644
--- a/Makefile
+++ b/Makefile
@@ -448,7 +448,7 @@ USERINCLUDE    := \
 LINUXINCLUDE    := \
 		-I$(srctree)/arch/$(SRCARCH)/include \
 		-I$(objtree)/arch/$(SRCARCH)/include/generated \
-		$(if $(KBUILD_SRC), -I$(srctree)/include) \
+		$(if $(filter .,$(srctree)),,-I$(srctree)/include) \
 		-I$(objtree)/include \
 		$(USERINCLUDE)
 
@@ -509,7 +509,7 @@ PHONY += outputmakefile
 # At the same time when output Makefile generated, generate .gitignore to
 # ignore whole output directory
 outputmakefile:
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 	$(Q)ln -fsn $(srctree) source
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 	$(Q)test -e .gitignore || \
@@ -1087,7 +1087,7 @@ PHONY += prepare archprepare prepare1 prepare3
 # and if so do:
 # 1) Check that make has not been executed in the kernel src $(srctree)
 prepare3: include/config/kernel.release
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 	@$(kecho) '  Using $(srctree) as source for kernel'
 	$(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
 		echo >&2 "  $(srctree) is not clean, please run 'make mrproper'"; \
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 76ca30c..9dddfb6 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -501,7 +501,7 @@ existing-targets := $(wildcard $(sort $(targets)))
 
 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 # Create directories for object files if they do not exist
 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
 # If targets exist, their directories apparently exist. Skip mkdir.
diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index a115259..73b8041 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -71,7 +71,7 @@ __hostc_flags	= $(_hostc_flags)
 __hostcxx_flags	= $(_hostcxx_flags)
 
 ifeq ($(KBUILD_EXTMOD),)
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 __hostc_flags	= -I$(obj) $(call flags,_hostc_flags)
 __hostcxx_flags	= -I$(obj) $(call flags,_hostcxx_flags)
 endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 8a1f64f..41e98fa 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -144,7 +144,7 @@ __cpp_flags     = $(_cpp_flags)
 # If building the kernel in a separate objtree expand all occurrences
 # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
 ifeq ($(KBUILD_EXTMOD),)
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 
 # -I$(obj) locates generated .h files
 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin
index a072a42..ea90a90 100644
--- a/scripts/Makefile.modbuiltin
+++ b/scripts/Makefile.modbuiltin
@@ -15,7 +15,7 @@ include include/config/tristate.conf
 
 include scripts/Kbuild.include
 
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 # Create output directory if not already present
 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
 endif
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile
index 3df395a..9fd3d8e 100644
--- a/scripts/gdb/linux/Makefile
+++ b/scripts/gdb/linux/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
 
 symlinks := $(patsubst $(srctree)/$(src)/%,%,$(wildcard $(srctree)/$(src)/*.py))
 
diff --git a/scripts/tags.sh b/scripts/tags.sh
index f470d99..6a55180 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -19,7 +19,7 @@ ignore="$ignore ( -name *.mod.c ) -prune -o"
 # Do not use full path if we do not use O=.. builds
 # Use make O=. {tags|cscope}
 # to force full paths for a non-O= build
-if [ "${KBUILD_SRC}" = "" ]; then
+if [ "${srctree}" = "." ]; then
 	tree=
 else
 	tree=${srctree}/
-- 
2.7.4

[PATCH 6/6] memory: squash drivers/memory/Makefile.asm-offsets

[Masahiro Yamada]

drivers/memory/Makefile.asm-offsets is small enough, and included
from a single place.

Squash it into drivers/memory/Makefile.

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

 drivers/memory/Makefile             | 5 ++++-
 drivers/memory/Makefile.asm-offsets | 4 ----
 2 files changed, 4 insertions(+), 5 deletions(-)
 delete mode 100644 drivers/memory/Makefile.asm-offsets

diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 90161de..aaf6771 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -28,6 +28,9 @@ ti-emif-sram-objs		:= ti-emif-pm.o ti-emif-sram-pm.o
 
 AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
 
-include drivers/memory/Makefile.asm-offsets
+include/generated/ti-emif-asm-offsets.h: drivers/memory/emif-asm-offsets.s FORCE
+	$(call filechk,offsets,__TI_EMIF_ASM_OFFSETS_H__)
+
+targets += emif-asm-offsets.s
 
 drivers/memory/ti-emif-sram-pm.o: include/generated/ti-emif-asm-offsets.h
diff --git a/drivers/memory/Makefile.asm-offsets b/drivers/memory/Makefile.asm-offsets
deleted file mode 100644
index 0447e17..0000000
--- a/drivers/memory/Makefile.asm-offsets
+++ /dev/null
@@ -1,4 +0,0 @@
-include/generated/ti-emif-asm-offsets.h: drivers/memory/emif-asm-offsets.s FORCE
-	$(call filechk,offsets,__TI_EMIF_ASM_OFFSETS_H__)
-
-targets += emif-asm-offsets.s
-- 
2.7.4

Re: [PATCH 2/6] kbuild: allow Kbuild to start from any directory

[Kieran Bingham]

Hi Yamada-san,

Thank you for the patches,

I like the direction this series is taking.

Small spelling error spotted below...
But as I've now gone through all of it I'll offer

Reviewed-by: Kieran Bingham <kbingham@kernel.org>


On 30/03/2019 12:04, Masahiro Yamada wrote:
> Kbuild always runs in the top of the output directory.
> 
> If Make starts in the source directory with O=, it relocates the
> working directory to the location specified by O=.
> 
> Also, users can start build from the output directory by using the
> Makefile generated by scripts/mkmakefile.
> 
> With a little more effort, Kbuild will be able to start from any
> directory path.
> 
> This commit allows to specify the source directory by using
> the -f option.
> 
> For example, you can do:
> 
>   $ cd path/to/output/dir
>   $ make -f path/to/source/dir/Makefile
> 
> Or, for the equivalent behavior, you can do:
> 
>   $ make O=path/to/output/dir -f path/to/source/dir/Makefile
> 
> KBUILD_SRC is now deprecated.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
>  Makefile | 87 +++++++++++++++++++++++++++++++++++++---------------------------
>  1 file changed, 50 insertions(+), 37 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 9cbd367..1b2a70e 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -96,56 +96,65 @@ endif
>  
>  export quiet Q KBUILD_VERBOSE
>  
> -# kbuild supports saving output files in a separate directory.
> -# To locate output files in a separate directory two syntaxes are supported.
> -# In both cases the working directory must be the root of the kernel src.
> +# Kbuild will save output files in the current working directory.
> +# This does not need to match to the root of the kernel source tree.
> +#
> +# For example, you can do this:
> +#
> +#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
> +#
> +# If you want to save output files in a different location, there are
> +# two syntaxes to specify it.
> +#
>  # 1) O=
>  # Use "make O=dir/to/store/output/files/"
>  #
>  # 2) Set KBUILD_OUTPUT
> -# Set the environment variable KBUILD_OUTPUT to point to the directory
> -# where the output files shall be placed.
> -# export KBUILD_OUTPUT=dir/to/store/output/files/
> -# make
> +# Set the environment variable KBUILD_OUTPUT to point to the output directory.
> +# export KBUILD_OUTPUT=dir/to/store/output/files/; make
>  #
>  # The O= assignment takes precedence over the KBUILD_OUTPUT environment
>  # variable.
>  
> -# KBUILD_SRC is not intended to be used by the regular user (for now),
> -# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
> -
> -# OK, Make called in directory where kernel src resides
> -# Do we want to locate output files in a separate directory?
> +# Do we want to change the working directory?
>  ifeq ("$(origin O)", "command line")
>    KBUILD_OUTPUT := $(O)
>  endif
>  
> -ifneq ($(words $(subst :, ,$(CURDIR))), 1)
> -  $(error main directory cannot contain spaces nor colons)
> +ifneq ($(KBUILD_OUTPUT),)
> +# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
> +# expand a shell special character '~'. We use a bit tredious way to handle it.

very minor, but I noticed while looking through the series ^^

s/bit tredious/somewhat tedious/



> +abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
> +$(if $(abs_objtree),, \
> +     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
> +
> +# $(realpath ...) resolves symlinks
> +abs_objtree := $(realpath $(abs_objtree))
> +else
> +abs_objtree := $(CURDIR)
> +endif # ifneq ($(KBUILD_OUTPUT),)
> +
> +ifeq ($(abs_objtree),$(CURDIR))
> +# Suppress "Entering directory ..." unless we are changing the work directory.
> +MAKEFLAGS += --no-print-directory
> +else
> +need-sub-make := 1
>  endif
>  
> -ifneq ($(KBUILD_OUTPUT),)
> -# check that the output directory actually exists
> -saved-output := $(KBUILD_OUTPUT)
> -KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
> -								&& pwd)
> -$(if $(KBUILD_OUTPUT),, \
> -     $(error failed to create output directory "$(saved-output)"))
> +abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
> +
> +ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
> +$(error source directory cannot contain spaces or colons)
> +endif
>  
> +ifneq ($(abs_srctree),$(abs_objtree))
>  # Look for make include files relative to root of kernel src
>  #
>  # This does not become effective immediately because MAKEFLAGS is re-parsed
> -# once after the Makefile is read.  It is OK since we are going to invoke
> -# 'sub-make' below.
> -MAKEFLAGS += --include-dir=$(CURDIR)
> -
> +# once after the Makefile is read. We need to invoke sub-make.
> +MAKEFLAGS += --include-dir=$(abs_srctree)
>  need-sub-make := 1
> -else
> -
> -# Do not print "Entering directory ..." at all for in-tree build.
> -MAKEFLAGS += --no-print-directory
> -
> -endif # ifneq ($(KBUILD_OUTPUT),)
> +endif
>  
>  ifneq ($(filter 3.%,$(MAKE_VERSION)),)
>  # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
> @@ -155,6 +164,7 @@ need-sub-make := 1
>  $(lastword $(MAKEFILE_LIST)): ;
>  endif
>  
> +export abs_srctree abs_objtree
>  export sub_make_done := 1
>  
>  ifeq ($(need-sub-make),1)
> @@ -166,9 +176,7 @@ $(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all:
>  
>  # Invoke a second make in the output directory, passing relevant variables
>  sub-make:
> -	$(Q)$(MAKE) \
> -	$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
> -	-f $(CURDIR)/Makefile $(MAKECMDGOALS)
> +	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
>  
>  endif # need-sub-make
>  endif # sub_make_done
> @@ -213,16 +221,21 @@ ifeq ("$(origin M)", "command line")
>    KBUILD_EXTMOD := $(M)
>  endif
>  
> -ifeq ($(KBUILD_SRC),)
> +ifeq ($(abs_srctree),$(abs_objtree))
>          # building in the source tree
>          srctree := .
>  else
> -        ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
> +        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
>                  # building in a subdirectory of the source tree
>                  srctree := ..
>          else
> -                srctree := $(KBUILD_SRC)
> +                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)
>  endif
>  
>  export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
> 


-- 
--
Kieran

Re: [PATCH 4/6] kbuild: mkmakefile: generate a simple wrapper of top Makefile

[Kieran Bingham]

Hi Yamada-san,

On 30/03/2019 12:04, Masahiro Yamada wrote:
> Now that Kbuild is able to start from any directory, the generated
> Makefile can simply wrap the top Makefile.

This is a really nice simplification :)

Reviewed-by: Kieran Bingham <kbingham@kernel.org>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
>  scripts/mkmakefile | 20 ++------------------
>  1 file changed, 2 insertions(+), 18 deletions(-)
> 
> diff --git a/scripts/mkmakefile b/scripts/mkmakefile
> index 31de468..4d0faeb 100755
> --- a/scripts/mkmakefile
> +++ b/scripts/mkmakefile
> @@ -12,22 +12,6 @@ if [ "${quiet}" != "silent_" ]; then
>  fi
>  
>  cat << EOF > Makefile
> -# Automatically generated by $0: don't edit
> -
> -ifeq ("\$(origin V)", "command line")
> -VERBOSE := \$(V)
> -endif
> -ifneq (\$(VERBOSE),1)
> -Q := @
> -endif
> -
> -MAKEFLAGS += --no-print-directory
> -
> -.PHONY: __sub-make \$(MAKECMDGOALS)
> -
> -__sub-make:
> -	\$(Q)\$(MAKE) -C $1 O=\$(CURDIR) \$(MAKECMDGOALS)
> -
> -\$(filter-out __sub-make, \$(MAKECMDGOALS)): __sub-make
> -	@:
> +# Automatically generated by $(realpath $0): don't edit
> +include $(realpath $1/Makefile)
>  EOF
> 


-- 
--
Kieran

Re: [PATCH 2/6] kbuild: allow Kbuild to start from any directory

[Masahiro Yamada]

Hi Kieran,


On Tue, Apr 2, 2019 at 1:41 PM Kieran Bingham <kbingham@kernel.org> wrote:
>
> Hi Yamada-san,
>
> Thank you for the patches,
>
> I like the direction this series is taking.
>
> Small spelling error spotted below...
> But as I've now gone through all of it I'll offer
>
> Reviewed-by: Kieran Bingham <kbingham@kernel.org>
>
>
> On 30/03/2019 12:04, Masahiro Yamada wrote:
> > Kbuild always runs in the top of the output directory.
> >
> > If Make starts in the source directory with O=, it relocates the
> > working directory to the location specified by O=.
> >
> > Also, users can start build from the output directory by using the
> > Makefile generated by scripts/mkmakefile.
> >
> > With a little more effort, Kbuild will be able to start from any
> > directory path.
> >
> > This commit allows to specify the source directory by using
> > the -f option.
> >
> > For example, you can do:
> >
> >   $ cd path/to/output/dir
> >   $ make -f path/to/source/dir/Makefile
> >
> > Or, for the equivalent behavior, you can do:
> >
> >   $ make O=path/to/output/dir -f path/to/source/dir/Makefile
> >
> > KBUILD_SRC is now deprecated.
> >
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> > ---
> >
> >  Makefile | 87 +++++++++++++++++++++++++++++++++++++---------------------------
> >  1 file changed, 50 insertions(+), 37 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 9cbd367..1b2a70e 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -96,56 +96,65 @@ endif
> >
> >  export quiet Q KBUILD_VERBOSE
> >
> > -# kbuild supports saving output files in a separate directory.
> > -# To locate output files in a separate directory two syntaxes are supported.
> > -# In both cases the working directory must be the root of the kernel src.
> > +# Kbuild will save output files in the current working directory.
> > +# This does not need to match to the root of the kernel source tree.
> > +#
> > +# For example, you can do this:
> > +#
> > +#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
> > +#
> > +# If you want to save output files in a different location, there are
> > +# two syntaxes to specify it.
> > +#
> >  # 1) O=
> >  # Use "make O=dir/to/store/output/files/"
> >  #
> >  # 2) Set KBUILD_OUTPUT
> > -# Set the environment variable KBUILD_OUTPUT to point to the directory
> > -# where the output files shall be placed.
> > -# export KBUILD_OUTPUT=dir/to/store/output/files/
> > -# make
> > +# Set the environment variable KBUILD_OUTPUT to point to the output directory.
> > +# export KBUILD_OUTPUT=dir/to/store/output/files/; make
> >  #
> >  # The O= assignment takes precedence over the KBUILD_OUTPUT environment
> >  # variable.
> >
> > -# KBUILD_SRC is not intended to be used by the regular user (for now),
> > -# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
> > -
> > -# OK, Make called in directory where kernel src resides
> > -# Do we want to locate output files in a separate directory?
> > +# Do we want to change the working directory?
> >  ifeq ("$(origin O)", "command line")
> >    KBUILD_OUTPUT := $(O)
> >  endif
> >
> > -ifneq ($(words $(subst :, ,$(CURDIR))), 1)
> > -  $(error main directory cannot contain spaces nor colons)
> > +ifneq ($(KBUILD_OUTPUT),)
> > +# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
> > +# expand a shell special character '~'. We use a bit tredious way to handle it.
>
> very minor, but I noticed while looking through the series ^^
>
> s/bit tredious/somewhat tedious/


Oops, 'tredious' is a typo.

As a non-native, I do not understand the difference
between 'a bit' and 'somewhat', but I will apply it.

Thanks.





-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/6] kbuild: pass $(MAKECMDGOALS) to sub-make as is

[Masahiro Yamada]

On Sat, Mar 30, 2019 at 9:04 PM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Manipulating $(MAKECMDGOALS) for sub-make seems odd to me.
>
> [1] 'make O=foo sub-make' is turned into 'make O=foo', which builds
> the default targets. It would make sense to terminate the build with:
>
>   *** No rule to make target 'sub-make'.  Stop.
>
> [2] 'make O=foo defconfig _all' is turned into 'make O=foo defconfig',
> which changes the behavior.
>
> Let's pass $(MAKECMDGOALS) as is.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---

Series, applied to linux-kbuild.


>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 92ad066..9cbd367 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -168,7 +168,7 @@ $(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all:
>  sub-make:
>         $(Q)$(MAKE) \
>         $(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
> -       -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
> +       -f $(CURDIR)/Makefile $(MAKECMDGOALS)
>
>  endif # need-sub-make
>  endif # sub_make_done
> --
> 2.7.4
>


-- 
Best Regards
Masahiro Yamada