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 $(realpath ...)
returns an empty string if the given path does not exist. It is
convenient in places where we need to error-out if the makefile fails
to create an output directory.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Thierry Reding <treding@nvidia.com>
diff --git a/Makefile b/Makefile
index 6eba23b..eca6cff 100644
--- a/Makefile
+++ b/Makefile
@@ -130,8 +130,8 @@
ifneq ($(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 @@
$(Q)$(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 @@
@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 @@
# 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
# ---------------------------------------------------------------------------
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile
index 8b00031..ab3cfe7 100644
--- a/scripts/gdb/linux/Makefile
+++ b/scripts/gdb/linux/Makefile
@@ -1,6 +1,6 @@
always := gdb-scripts
-SRCTREE := $(shell cd $(srctree) && /bin/pwd)
+SRCTREE := $(abspath $(srctree))
$(obj)/gdb-scripts:
ifneq ($(KBUILD_SRC),)
diff --git a/tools/power/cpupower/Makefile b/tools/power/cpupower/Makefile
index d6e1c02..4c5a481 100644
--- a/tools/power/cpupower/Makefile
+++ b/tools/power/cpupower/Makefile
@@ -26,7 +26,7 @@
ifneq ($(OUTPUT),)
# check that the output directory actually exists
-OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
+OUTDIR := $(realpath $(OUTPUT))
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index ccad8ce..57a8509 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -1,7 +1,7 @@
ifneq ($(O),)
ifeq ($(origin O), command line)
- dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
- ABSOLUTE_O := $(shell cd $(O) ; pwd)
+ ABSOLUTE_O := $(realpath $(O))
+ dummy := $(if $(ABSOLUTE_O),,$(error O=$(O) does not exist))
OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
COMMAND_O := O=$(ABSOLUTE_O)
ifeq ($(objtree),)
@@ -12,7 +12,7 @@
# check that the output directory actually exists
ifneq ($(OUTPUT),)
-OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
+OUTDIR := $(realpath $(OUTPUT))
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif
