linux.git/arch/s390/kernel/syscalls/Makefile, branch v6.12

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

2024-05-09T19:34:52+00:00

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada 
Reviewed-by: Nicolas Schier

arch: syscalls: simplify uapi/kapi directory creation

2022-03-31T03:03:46+00:00

$(shell ...) expands to empty. There is no need to assign it to _dummy.

Signed-off-by: Masahiro Yamada 
Acked-by: Geert Uytterhoeven

kbuild: use assignment instead of define ... endef for filechk_* rules

2019-01-06T01:22:35+00:00

You do not have to use define ... endef for filechk_* rules.

For simple cases, the use of assignment looks cleaner, IMHO.

I updated the usage for scripts/Kbuild.include in case somebody
misunderstands the 'define ... endif' is the requirement.

Signed-off-by: Masahiro Yamada 
Acked-by: Heiko Carstens

kbuild: do not redirect the first prerequisite for filechk

2018-07-28T01:34:10+00:00

Currently, filechk unconditionally opens the first prerequisite and
redirects it as the stdin of a filechk_* rule.  Hence, every target
using $(call filechk,...) must list something as the first prerequisite
even if it is unneeded.

'< $<' is actually unneeded in most cases.  Each rule can explicitly
adds it if necessary.

Signed-off-by: Masahiro Yamada

s390/syscalls: add Makefile to generate system call header files

2018-01-23T06:36:51+00:00

Generate the system call specific files from the archheaders
and archprepare make targets.

Signed-off-by: Hendrik Brueckner 
Acked-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky