| Message ID | 20231214140305.531963-1-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: resolve symlinks for O= properly | expand |
On Thu, Dec 14, 2023 at 11:03:05PM +0900, Masahiro Yamada wrote: > Currently, Kbuild follows the logical chain of directories for the O= > option, just like 'cd' (or 'realpath --logical') does. > > Example: > > $ mkdir -p /tmp/a /tmp/x/y > $ ln -s /tmp/x/y /tmp/a/b > $ realpath /tmp/a/b/.. > /tmp/x > $ realpath --logical /tmp/a/b/.. > /tmp/a > $ make O=/tmp/a/b/.. defconfig > make[1]: Entering directory '/tmp/a' > [snip] > make[1]: Leaving directory '/tmp/a' > > 'make O=/tmp/a/b/.. defconfig' creates the kernel configuration in > /tmp/a instead of /tmp/x despite the directory path /tmp/a/b/.. > resolves to the physical directory path /tmp/x. > > This is because Kbuild internally uses the 'cd ... && pwd' for the > path resolution, but this behavior is not predictable for users. > Additionally, it is not consistent with how the Kbuild handles the > M= option or GNU Make works with 'make -C /tmp/a/b/..'. > > Using the physical directory structure for the O= option seems more > reasonable. > > The comment says "expand a shell special character '~'", but it has > already been expanded to the home directory in the command line. I minor change in behaviour is that 'make O="~/..."' (=quoted '~) will not work any more. But I think this actually the way it should be. Thanks! Reviewed-by: Nicolas Schier <n.schier@avm.de> > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > --- > > Makefile | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/Makefile b/Makefile > index 24fac1889997..a05f0f7c99e0 100644 > --- a/Makefile > +++ b/Makefile > @@ -190,14 +190,11 @@ ifeq ("$(origin O)", "command line") > endif > > ifneq ($(KBUILD_OUTPUT),) > -# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot > -# expand a shell special character '~'. We use a somewhat tedious way here. > -abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd) > -$(if $(abs_objtree),, \ > - $(error failed to create output directory "$(KBUILD_OUTPUT)")) > - > +# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first. > +$(shell mkdir -p $(KBUILD_OUTPUT)) > # $(realpath ...) resolves symlinks > -abs_objtree := $(realpath $(abs_objtree)) > +abs_objtree := $(realpath $(KBUILD_OUTPUT)) > +$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)")) > endif # ifneq ($(KBUILD_OUTPUT),) > > ifneq ($(words $(subst :, ,$(abs_srctree))), 1) > -- > 2.40.1 >
On Fri, Dec 15, 2023 at 6:29 PM Nicolas Schier <n.schier@avm.de> wrote: > > On Thu, Dec 14, 2023 at 11:03:05PM +0900, Masahiro Yamada wrote: > > Currently, Kbuild follows the logical chain of directories for the O= > > option, just like 'cd' (or 'realpath --logical') does. > > > > Example: > > > > $ mkdir -p /tmp/a /tmp/x/y > > $ ln -s /tmp/x/y /tmp/a/b > > $ realpath /tmp/a/b/.. > > /tmp/x > > $ realpath --logical /tmp/a/b/.. > > /tmp/a > > $ make O=/tmp/a/b/.. defconfig > > make[1]: Entering directory '/tmp/a' > > [snip] > > make[1]: Leaving directory '/tmp/a' > > > > 'make O=/tmp/a/b/.. defconfig' creates the kernel configuration in > > /tmp/a instead of /tmp/x despite the directory path /tmp/a/b/.. > > resolves to the physical directory path /tmp/x. > > > > This is because Kbuild internally uses the 'cd ... && pwd' for the > > path resolution, but this behavior is not predictable for users. > > Additionally, it is not consistent with how the Kbuild handles the > > M= option or GNU Make works with 'make -C /tmp/a/b/..'. > > > > Using the physical directory structure for the O= option seems more > > reasonable. > > > > The comment says "expand a shell special character '~'", but it has > > already been expanded to the home directory in the command line. > > I minor change in behaviour is that 'make O="~/..."' (=quoted '~) will > not work any more. But I think this actually the way it should be. > Thanks! A good catch. This bug should be fixed by quoting $(KBUILD_OUTPUT). -$(shell mkdir -p $(KBUILD_OUTPUT)) +$(shell mkdir -p "$(KBUILD_OUTPUT)") When ~ is quoted, it loses a special meaning. masahiro@zoe:~$ echo ~ /home/masahiro masahiro@zoe:~$ echo "~" ~ So, the right behaviour of 'make O="~/foo"' is to create "~/foo" under the current directory. If you try to test it, please be careful to not delete your home directory. (I did "rm -r ./~" just in case) > Reviewed-by: Nicolas Schier <n.schier@avm.de> > > > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > > --- > > > > Makefile | 11 ++++------- > > 1 file changed, 4 insertions(+), 7 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index 24fac1889997..a05f0f7c99e0 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -190,14 +190,11 @@ ifeq ("$(origin O)", "command line") > > endif > > > > ifneq ($(KBUILD_OUTPUT),) > > -# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot > > -# expand a shell special character '~'. We use a somewhat tedious way here. > > -abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd) > > -$(if $(abs_objtree),, \ > > - $(error failed to create output directory "$(KBUILD_OUTPUT)")) > > - > > +# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first. > > +$(shell mkdir -p $(KBUILD_OUTPUT)) > > # $(realpath ...) resolves symlinks > > -abs_objtree := $(realpath $(abs_objtree)) > > +abs_objtree := $(realpath $(KBUILD_OUTPUT)) > > +$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)")) > > endif # ifneq ($(KBUILD_OUTPUT),) > > > > ifneq ($(words $(subst :, ,$(abs_srctree))), 1) > > -- > > 2.40.1 > >
diff --git a/Makefile b/Makefile index 24fac1889997..a05f0f7c99e0 100644 --- a/Makefile +++ b/Makefile @@ -190,14 +190,11 @@ ifeq ("$(origin O)", "command line") endif ifneq ($(KBUILD_OUTPUT),) -# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot -# expand a shell special character '~'. We use a somewhat tedious way here. -abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd) -$(if $(abs_objtree),, \ - $(error failed to create output directory "$(KBUILD_OUTPUT)")) - +# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first. +$(shell mkdir -p $(KBUILD_OUTPUT)) # $(realpath ...) resolves symlinks -abs_objtree := $(realpath $(abs_objtree)) +abs_objtree := $(realpath $(KBUILD_OUTPUT)) +$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)")) endif # ifneq ($(KBUILD_OUTPUT),) ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
Currently, Kbuild follows the logical chain of directories for the O= option, just like 'cd' (or 'realpath --logical') does. Example: $ mkdir -p /tmp/a /tmp/x/y $ ln -s /tmp/x/y /tmp/a/b $ realpath /tmp/a/b/.. /tmp/x $ realpath --logical /tmp/a/b/.. /tmp/a $ make O=/tmp/a/b/.. defconfig make[1]: Entering directory '/tmp/a' [snip] make[1]: Leaving directory '/tmp/a' 'make O=/tmp/a/b/.. defconfig' creates the kernel configuration in /tmp/a instead of /tmp/x despite the directory path /tmp/a/b/.. resolves to the physical directory path /tmp/x. This is because Kbuild internally uses the 'cd ... && pwd' for the path resolution, but this behavior is not predictable for users. Additionally, it is not consistent with how the Kbuild handles the M= option or GNU Make works with 'make -C /tmp/a/b/..'. Using the physical directory structure for the O= option seems more reasonable. The comment says "expand a shell special character '~'", but it has already been expanded to the home directory in the command line. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- Makefile | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)