From 7beba04eb305393e3f8386390f25b4a9475f27f2 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 16 Dec 2023 01:06:37 +0900 Subject: kbuild: resolve symlinks for O= properly 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 /tmp/a/b/.. resolves to /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 Reviewed-by: Nicolas Schier --- Makefile | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 5a11804af640a..6204a3803a90f 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) -- cgit 1.2.3-korg