linux/samples
Masahiro Yamada b1992c3772 kbuild: use $(src) instead of $(srctree)/$(src) for source directory
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:34:52 +09:00
..
acrn
auxdisplay
binderfs
bpf kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
cgroup samples/cgroup: add .gitignore file for generated samples 2024-01-24 11:52:40 -08:00
configfs
connector
coresight
fanotify
fprobe
ftrace RISC-V Patches for the 6.8 Merge Window, Part 4 2024-01-20 11:06:04 -08:00
hid kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
hidraw
hw_breakpoint
kdb
kfifo
kmemleak
kobject
kprobes
landlock samples/landlock: Don't error out if a file path cannot be opened 2024-03-08 18:22:18 +01:00
livepatch
mei
nitro_enclaves
pfsm
pidfd
pktgen
qmi
rpmsg
rust
seccomp samples: user-trap: fix strict-aliasing warning 2024-02-12 10:42:02 -08:00
timers
trace_events tracing: Remove second parameter to __assign_rel_str() 2024-03-18 10:33:05 -04:00
trace_printk
uhid
user_events
v4l media updates for v6.8-rc1 2024-01-12 14:29:48 -08:00
vfio-mdev vfio/mbochs: make mbochs_class constant 2024-03-05 15:15:27 -07:00
vfs
watch_queue
watchdog
Kconfig samples: introduce new samples subdir for cgroup 2023-12-10 16:51:54 -08:00
Makefile samples: introduce new samples subdir for cgroup 2023-12-10 16:51:54 -08:00