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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-07-06 12:07:13 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-07-11 00:05:09 +0900 |
| commit | 95fd3f87bfbe8edaa5e955e0f858a0a573c09ab6 (patch) | |
| tree | f716e4fb759895a5f8354d0b4612c91ddf315295 | |
| parent | 051f278e9d81bed253bf89c66c80b8b921aafa8a (diff) | |
| download | lwn-95fd3f87bfbe8edaa5e955e0f858a0a573c09ab6.tar.gz lwn-95fd3f87bfbe8edaa5e955e0f858a0a573c09ab6.zip | |
kbuild: add a flag to force absolute path for srctree
In old days, Kbuild always used an absolute path for $(srctree).
Since commit 890676c65d69 ("kbuild: Use relative path when building in
the source tree"), $(srctree) is '.' when O= was not passed from the
command line.
Yet, using absolute paths is useful in some cases even without O=, for
instance, to create a cscope file with absolute path tags.
'O=.' was known to work as a workaround to force Kbuild to use absolute
paths even when you are building in the source tree.
Since commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any
directory"), Kbuild is too clever to be tricked. Even if you pass 'O=.'
Kbuild notices you are building in the source tree, then use '.' for
$(srctree).
So, 'make O=. cscope' is no help to create absolute path tags.
We cannot force one or the other according to commit e93bc1a0cab3
("Revert "kbuild: specify absolute paths for cscope""). Both of
relative path and absolute path have pros and cons.
This commit adds a new flag KBUILD_ABS_SRCTREE to allow users to
choose the absolute path for $(srctree).
'make KBUILD_ABS_SRCTREE=1 cscope' will work as a replacement of
'make O=. cscope'.
Reported-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| -rw-r--r-- | Documentation/kbuild/kbuild.txt | 9 | ||||
| -rw-r--r-- | Makefile | 4 | ||||
| -rwxr-xr-x | scripts/tags.sh | 3 |
3 files changed, 14 insertions, 2 deletions
diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt index 9c230ea71963..dcfeb32e3360 100644 --- a/Documentation/kbuild/kbuild.txt +++ b/Documentation/kbuild/kbuild.txt @@ -183,6 +183,15 @@ The output directory is often set using "O=..." on the commandline. The value can be overridden in which case the default value is ignored. +KBUILD_ABS_SRCTREE +-------------------------------------------------- +Kbuild uses a relative path to point to the tree when possible. For instance, +when building in the source tree, the source tree path is '.' + +Setting this flag requests Kbuild to use absolute path to the source tree. +There are some useful cases to do so, like when generating tag files with +absolute path entries etc. + KBUILD_SIGN_PIN -------------------------------------------------- This variable allows a passphrase or PIN to be passed to the sign-file @@ -244,6 +244,10 @@ else building_out_of_srctree := 1 endif +ifneq ($(KBUILD_ABS_SRCTREE),) +srctree := $(abs_srctree) +endif + objtree := . VPATH := $(srctree) diff --git a/scripts/tags.sh b/scripts/tags.sh index 7fea4044749b..4e18ae5282a6 100755 --- a/scripts/tags.sh +++ b/scripts/tags.sh @@ -17,8 +17,7 @@ ignore="$(echo "$RCS_FIND_IGNORE" | sed 's|\\||g' )" # tags and cscope files should also ignore MODVERSION *.mod.c files ignore="$ignore ( -name *.mod.c ) -prune -o" -# Do not use full path if we do not use O=.. builds -# Use make O=. {tags|cscope} +# Use make KBUILD_ABS_SRCTREE=1 {tags|cscope} # to force full paths for a non-O= build if [ "${srctree}" = "." -o -z "${srctree}" ]; then tree= |