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author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-08-20 15:04:11 +0900 |
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committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-09-01 08:50:32 +0900 |
commit | 8e9b466799230bc20a029579e92d4cd526e5a2e1 (patch) | |
tree | 3b51d498c991f1e22bf482c0e59e0c2d203faac4 /Makefile | |
parent | aae4e7a8bc44722fe70d58920a36916b1043195e (diff) | |
download | lwn-8e9b466799230bc20a029579e92d4cd526e5a2e1.tar.gz lwn-8e9b466799230bc20a029579e92d4cd526e5a2e1.zip |
kbuild: use $(abspath ...) instead of $(shell cd ... && /bin/pwd)
Kbuild conventionally uses $(shell cd ... && /bin/pwd) idiom to get
the absolute path of the directory because GNU Make 3.80, the minimal
supported version at that time, did not support $(abspath ...) or
$(realpath ...).
Commit 37d69ee30808 ("docs: bump minimal GNU Make version to 3.81")
dropped the GNU Make 3.80 support, so we are now allowed to use those
make-builtin helpers.
This conversion will provide better portability without relying on
the pwd command or its location /bin/pwd.
I am intentionally using $(realpath ...) instead $(abspath ...) in
some places. The difference between the two is $(realpath ...)
returns an empty string if the given path does not exist. It is
convenient in places where we need to error-out if the makefile fails
to create an output directory.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'Makefile')
-rw-r--r-- | Makefile | 12 |
1 files changed, 6 insertions, 6 deletions
@@ -130,8 +130,8 @@ endif ifneq ($(KBUILD_OUTPUT),) # check that the output directory actually exists saved-output := $(KBUILD_OUTPUT) -KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \ - && /bin/pwd) +$(shell [ -d $(KBUILD_OUTPUT) ] || mkdir -p $(KBUILD_OUTPUT)) +KBUILD_OUTPUT := $(realpath $(KBUILD_OUTPUT)) $(if $(KBUILD_OUTPUT),, \ $(error failed to create output directory "$(saved-output)")) @@ -978,7 +978,7 @@ ifdef CONFIG_HEADERS_CHECK $(Q)$(MAKE) -f $(srctree)/Makefile headers_check endif ifdef CONFIG_GDB_SCRIPTS - $(Q)ln -fsn `cd $(srctree) && /bin/pwd`/scripts/gdb/vmlinux-gdb.py + $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py) endif ifdef CONFIG_TRIM_UNUSED_KSYMS $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \ @@ -1237,7 +1237,7 @@ _modinst_: @rm -rf $(MODLIB)/kernel @rm -f $(MODLIB)/source @mkdir -p $(MODLIB)/kernel - @ln -s `cd $(srctree) && /bin/pwd` $(MODLIB)/source + @ln -s $(abspath $(srctree)) $(MODLIB)/source @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \ rm -f $(MODLIB)/build ; \ ln -s $(CURDIR) $(MODLIB)/build ; \ @@ -1629,11 +1629,11 @@ image_name: # Clear a bunch of variables before executing the submake tools/: FORCE $(Q)mkdir -p $(objtree)/tools - $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/ + $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ tools/%: FORCE $(Q)mkdir -p $(objtree)/tools - $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/ $* + $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $* # Single targets # --------------------------------------------------------------------------- |