diff mbox series

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

Message ID 1553947458-8311-2-git-send-email-yamada.masahiro@socionext.com
State Accepted
Commit 25b146c5b8ceecd43c311552d325a4e403c639f2
Headers show
Series [1/6] kbuild: pass $(MAKECMDGOALS) to sub-make as is | expand

Commit Message

Masahiro Yamada March 30, 2019, 12:04 p.m. UTC 
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(-)

-- 
2.7.4

Comments

Kieran Bingham April 2, 2019, 4:41 a.m. UTC | #1 
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
Masahiro Yamada April 2, 2019, 2:23 p.m. UTC | #2 
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
diff mbox series

Patch

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