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| author | Masahiro Yamada <masahiroy@kernel.org> | 2022-12-13 20:24:20 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-12-14 15:42:40 +0900 |
| commit | 87d599fc3955e59b1ed30f350321a4be5353f945 (patch) | |
| tree | f43f5dc1ec8a0e381d011c63f4f4989964c025eb /Makefile | |
| parent | 3d57e1b7b1d42d4040f0d993b66ff06beda02c54 (diff) | |
| download | lwn-87d599fc3955e59b1ed30f350321a4be5353f945.tar.gz lwn-87d599fc3955e59b1ed30f350321a4be5353f945.zip | |
kbuild: ensure Make >= 3.82 is used
Documentation/process/changes.rst notes the minimal GNU Make version,
but it is not checked anywhere.
We could check $(MAKE_VERSION), but another simple way is to check
$(.FEATURES) since the feature list always grows.
GNU Make 3.81 expands $(.FEATURES) to:
target-specific order-only second-expansion else-if archives jobserver check-symlink
GNU Make 3.82 expands $(.FEATURES) to:
target-specific order-only second-expansion else-if shortest-stem undefine archives jobserver check-symlink
To ensure Make >= 3.82, you can check either 'shortest-stem' or
'undefine'.
This way is not always possible. For example, Make 4.0 through 4.2 have
the same set of $(.FEATURES). At that point, we will need to come up
with a different approach.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 4 |
1 files changed, 4 insertions, 0 deletions
@@ -11,6 +11,10 @@ NAME = Hurr durr I'ma ninja sloth # Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. +ifeq ($(filter undefine,$(.FEATURES)),) +$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION)) +endif + $(if $(filter __%, $(MAKECMDGOALS)), \ $(error targets prefixed with '__' are only for internal use)) |