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| author | Masahiro Yamada <masahiroy@kernel.org> | 2022-12-11 03:54:47 +0100 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-12-13 14:29:10 +0100 |
| commit | 6768fa4bcb6c1618248f135d04b9287ba2724ae0 (patch) | |
| tree | 0d49fcbba647b32e81d9da19192092dce67485e4 /scripts/Kbuild.include | |
| parent | kbuild: do not sort after reading modules.order (diff) | |
| download | linux-6768fa4bcb6c1618248f135d04b9287ba2724ae0.tar.xz linux-6768fa4bcb6c1618248f135d04b9287ba2724ae0.zip | |
kbuild: add read-file macro
Since GNU Make 4.2, $(file ...) supports the read operater '<', which
is useful to read a file without forking a new process. No warning is
shown even if the input file is missing.
For older Make versions, it falls back to the cat command.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Tested-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Diffstat (limited to 'scripts/Kbuild.include')
| -rw-r--r-- | scripts/Kbuild.include | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 3be7c2d75667..21e76ba0de17 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -10,6 +10,10 @@ empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ pound := \# +define newline + + +endef ### # Comparison macros. @@ -62,6 +66,16 @@ kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile) ### +# Read a file, replacing newlines with spaces +# +# Make 4.2 or later can read a file by using its builtin function. +ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),) +read-file = $(subst $(newline),$(space),$(file < $1)) +else +read-file = $(shell cat $1 2>/dev/null) +endif + +### # Easy method for doing a status message kecho := : quiet_kecho := echo |