Re: [PATCH] kbuild: revert $(realpath ...) to $(shell cd ... && /bin/pwd)

From: Julien Grall
Date: Mon Oct 02 2017 - 07:27:33 EST


Hello,

On 02/10/17 09:07, Masahiro Yamada wrote:
I thought commit 8e9b46679923 ("kbuild: use $(abspath ...) instead of
$(shell cd ... && /bin/pwd)") was a safe conversion, but it changed
the behavior.

$(abspath ...) / $(realpath ...) does not expand shell special
characters, such as '~'.

Here is a simple Makefile example:

---------------->8----------------
$(info /bin/pwd: $(shell cd ~/; /bin/pwd))
$(info abspath: $(abspath ~/))
$(info realpath: $(realpath ~/))
all:
@:
---------------->8----------------

$ make
/bin/pwd: /home/masahiro
abspath: /home/masahiro/workspace/~
realpath:

This can be a real problem if 'make O=~/foo' is invoked from another
Makefile or primitive shell like dash.

This commit partially reverts 8e9b46679923.

Fixes: 8e9b46679923 ("kbuild: use $(abspath ...) instead of $(shell cd ... && /bin/pwd)")
Reported-by: Julien Grall <julien.grall@xxxxxxx>
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

Tested-by: Julien Grall <julien.grall@xxxxxxx>

Regards,

---

Makefile | 4 ++--
tools/power/cpupower/Makefile | 2 +-
tools/scripts/Makefile.include | 6 +++---
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index cf007a3..1b48717 100644
--- a/Makefile
+++ b/Makefile
@@ -130,8 +130,8 @@ endif
ifneq ($(KBUILD_OUTPUT),)
# check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
-$(shell [ -d $(KBUILD_OUTPUT) ] || mkdir -p $(KBUILD_OUTPUT))
-KBUILD_OUTPUT := $(realpath $(KBUILD_OUTPUT))
+KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
+ && /bin/pwd)
$(if $(KBUILD_OUTPUT),, \
$(error failed to create output directory "$(saved-output)"))
diff --git a/tools/power/cpupower/Makefile b/tools/power/cpupower/Makefile
index 4c5a481..d6e1c02 100644
--- a/tools/power/cpupower/Makefile
+++ b/tools/power/cpupower/Makefile
@@ -26,7 +26,7 @@ endif
ifneq ($(OUTPUT),)
# check that the output directory actually exists
-OUTDIR := $(realpath $(OUTPUT))
+OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 9dc8f07..1e8b611 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -1,7 +1,7 @@
ifneq ($(O),)
ifeq ($(origin O), command line)
- ABSOLUTE_O := $(realpath $(O))
- dummy := $(if $(ABSOLUTE_O),,$(error O=$(O) does not exist))
+ dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
+ ABSOLUTE_O := $(shell cd $(O) ; pwd)
OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
COMMAND_O := O=$(ABSOLUTE_O)
ifeq ($(objtree),)
@@ -12,7 +12,7 @@ endif
# check that the output directory actually exists
ifneq ($(OUTPUT),)
-OUTDIR := $(realpath $(OUTPUT))
+OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif


--
Julien Grall