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authorMasahiro Yamada <yamada.masahiro@socionext.com>2017-08-20 15:04:11 +0900
committerMasahiro Yamada <yamada.masahiro@socionext.com>2017-09-01 08:50:32 +0900
commit8e9b466799230bc20a029579e92d4cd526e5a2e1 (patch)
tree3b51d498c991f1e22bf482c0e59e0c2d203faac4 /Makefile
parentaae4e7a8bc44722fe70d58920a36916b1043195e (diff)
downloadlwn-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 $(realpath ...) returns an empty string if the given path does not exist. It is convenient in places where we need to error-out if the makefile fails to create an output directory. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'Makefile')
-rw-r--r--Makefile12
1 files changed, 6 insertions, 6 deletions
diff --git a/Makefile b/Makefile
index 6eba23bcb5ad..eca6cffa3cd7 100644
--- a/Makefile
+++ b/Makefile
@@ -130,8 +130,8 @@ endif
ifneq ($(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
# ---------------------------------------------------------------------------