Re: [XEN PATCH v9 09/30] build: build everything from the root dir, use obj=$subdir

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 1/25/22 06:00, Anthony PERARD wrote:
> A subdirectory is now built by setting "$(obj)" instead of changing
> directory. "$(obj)" should always be set when using "Rules.mk" and
> thus a shortcut "$(build)" is introduced and should be used.
> 
> A new variable "$(need-builtin)" is introduce. It is to be used
> whenever a "built_in.o" is wanted from a subdirectory. "built_in.o"
> isn't the main target anymore, and thus only needs to depends on the
> objects that should be part of "built_in.o".
> 
> Introduce $(srctree) and $(objtree) to replace $(BASEDIR) in cases a
> relative path is better, and $(abs_srctree) and $(abs_objtree) which
> have an absolute path.
> 
> DEPS is updated as the existing macro to deal with it doesn't know
> about $(obj).
> 
> There's some changes in "Rules.mk" which in addition to deal with
> "$(obj)" also make it's looks more like "Makefile.build" from Linux
> v5.12.
> 
> test/Makefile doesn't need special handling in order to build
> everything under test/, Rules.mk will visit test/livepatch via
> $(subdir-y), thus "tests" "all" and "build" target are removed.
> "subtree-force-update" target isn't useful so it is removed as well.
> 
> test/livepatch/Makefile doesn't need default target anymore, Rules.mk
> will build everything in $(extra-y) and thus all *.livepatch.
> 
> Adjust cloc recipe: dependency files generated by CC will now have the
> full path to the source file, so we don't need to prepend the
> subdirectory. This fix some issue with source not been parsed by cloc
> before. Also source from tools/kconfig would be listed with changes in
> this patch so adjust the find command to stop listing the "tools"
> directory and thus kconfig. With a default build of Xen on X86, they
> are a few new files parsed by cloc:
>     arch/x86/x86_64/compat/mm.c
>     arch/x86/x86_64/mm.c
>     common/compat/domain.c
>     common/compat/memory.c
>     common/compat/xlat.c
> 
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> Acked-by: Bob Eshleman <bobbyeshleman@xxxxxxxxx>
> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
> ---
> 
> Notes:
>     v9:
>     - reviewed
>     
>     v8:
>     - rebased
>     - move check for $(obj) in Rules.mk earlier
>     - use $(sort ) when adding directories in $(subdir-y)
>     - fix missing space between "DEPS" and ":="
>     - use -iquote when adding '.' for xen/arch/x86/usercopy.o
>     - introduce also abs_srctree and abs_objtree
>       those were in patch "build: replace $(BASEDIR) by $(objtree)"
>     - reworked cmd_objcopy_fix_sym, we don't need to do anything for old
>       version of clang, and for recent version of clang the change is the
>       same a for gcc.
>     - adjust "cloc" recipe
>     - add some more $(Q) to silent $(MAKE) $(build)=...
>     
>     v7:
>     - Spell "Makefile.build" as "Rules.mk" in the warning in Rules.mk about
>       undefined $(obj).
>     - use $(srctree) for include/xen/config.h
>     - handle $(nocov-y) and $(noubsan-y), needed to add $(obj)/
> 
>  xen/Makefile                |  36 ++++++----
>  xen/Rules.mk                | 138 ++++++++++++++++++++++++------------
>  xen/arch/arm/Makefile       |   4 +-
>  xen/arch/arm/Rules.mk       |   4 --
>  xen/arch/arm/arch.mk        |   4 +-
>  xen/arch/riscv/arch.mk      |   4 +-
>  xen/arch/x86/Makefile       |  11 +--
>  xen/arch/x86/Rules.mk       |   4 +-
>  xen/arch/x86/arch.mk        |  12 ++--
>  xen/arch/x86/boot/Makefile  |   8 +--
>  xen/build.mk                |  12 +++-
>  xen/include/Makefile        |   6 +-
>  xen/scripts/Kbuild.include  |   6 ++
>  xen/test/Makefile           |   7 +-
>  xen/test/livepatch/Makefile |   6 --
>  xen/xsm/flask/Makefile      |   2 +-
>  xen/xsm/flask/ss/Makefile   |   2 +-
>  17 files changed, 162 insertions(+), 104 deletions(-)
> 

<snip/>

> diff --git a/xen/xsm/flask/Makefile b/xen/xsm/flask/Makefile
> index 51fd37f6c4d5..49cf730cf098 100644
> --- a/xen/xsm/flask/Makefile
> +++ b/xen/xsm/flask/Makefile
> @@ -40,7 +40,7 @@ $(obj)/flask-policy.S: $(BASEDIR)/tools/binfile FORCE
>       $(call if_changed,binfile,$(obj)/policy.bin xsm_flask_init_policy)
>  targets += flask-policy.S
>  
> -FLASK_BUILD_DIR := $(CURDIR)
> +FLASK_BUILD_DIR := $(abs_objtree)/$(obj)
>  POLICY_SRC := $(FLASK_BUILD_DIR)/xenpolicy-$(XEN_FULLVERSION)
>  
>  $(obj)/policy.bin: FORCE
> diff --git a/xen/xsm/flask/ss/Makefile b/xen/xsm/flask/ss/Makefile
> index d32b9e07138e..aba1339f3808 100644
> --- a/xen/xsm/flask/ss/Makefile
> +++ b/xen/xsm/flask/ss/Makefile
> @@ -8,4 +8,4 @@ obj-y += services.o
>  obj-y += conditional.o
>  obj-y += mls.o
>  
> -CFLAGS-y += -I../include
> +CFLAGS-y += -I$(srctree)/xsm/flask/include


Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>

V/r,
Daniel P. Smith
Apertus Solutions, LLC