Re-run Kconfig if we detect the Rust compiler has changed via the version
text, like it is done for C.
Unlike C, and unlike `RUSTC_VERSION`, the `RUSTC_VERSION_TEXT` is kept
under `depends on RUST`, since it should not be needed unless `RUST`
is enabled.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
Masahiro: I think leaving the `depends on RUST` in `RUSTC_VERSION` is
OK, but since this is different from the C side, please let me know if
you prefer otherwise. Thanks!
Makefile | 5 +++--
init/Kconfig | 4 +++-
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index 8ad55d6e7b60..2b5f9f098b6f 100644
--- a/Makefile
+++ b/Makefile
@@ -648,9 +648,10 @@ endif
# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
-# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
+# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they need export),
# and from include/config/auto.conf.cmd to detect the compiler upgrade.
CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
+RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(RUSTC) --version 2>/dev/null | head -n 1))
ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
include $(srctree)/scripts/Makefile.clang
@@ -671,7 +672,7 @@ ifdef config-build
# KBUILD_DEFCONFIG may point out an alternative default configuration
# used for 'make defconfig'
include $(srctree)/arch/$(SRCARCH)/Makefile
-export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
+export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
config: outputmakefile scripts_basic FORCE
$(Q)$(MAKE) $(build)=scripts/kconfig $@
diff --git a/init/Kconfig b/init/Kconfig
index 2f974f412374..b0238c4b6e79 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1926,7 +1926,9 @@ config RUST
config RUSTC_VERSION_TEXT
string
depends on RUST
- default "$(shell,LC_ALL=C $(RUSTC) --version 2>/dev/null | head -n 1)"
+ default "$(RUSTC_VERSION_TEXT)"
+ help
+ See `CC_VERSION_TEXT`.
config BINDGEN_VERSION_TEXT
string
--
2.46.0On Fri, Aug 09, 2024 at 12:11:35AM +0200, Miguel Ojeda wrote: > Re-run Kconfig if we detect the Rust compiler has changed via the version > text, like it is done for C. > > Unlike C, and unlike `RUSTC_VERSION`, the `RUSTC_VERSION_TEXT` is kept > under `depends on RUST`, since it should not be needed unless `RUST` > is enabled. > > Signed-off-by: Miguel Ojeda <ojeda@kernel.org> > --- > Masahiro: I think leaving the `depends on RUST` in `RUSTC_VERSION` is > OK, but since this is different from the C side, please let me know if > you prefer otherwise. Thanks! > > Makefile | 5 +++-- > init/Kconfig | 4 +++- > 2 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/Makefile b/Makefile > index 8ad55d6e7b60..2b5f9f098b6f 100644 > --- a/Makefile > +++ b/Makefile > @@ -648,9 +648,10 @@ endif > > # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included. > # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile. > -# CC_VERSION_TEXT is referenced from Kconfig (so it needs export), > +# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they need export), > # and from include/config/auto.conf.cmd to detect the compiler upgrade. If you send a v2, mind you consider reformatting so that this comment block stays <= 80 chars? > CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1)) > +RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(RUSTC) --version 2>/dev/null | head -n 1)) > > ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) > include $(srctree)/scripts/Makefile.clang > @@ -671,7 +672,7 @@ ifdef config-build > # KBUILD_DEFCONFIG may point out an alternative default configuration > # used for 'make defconfig' > include $(srctree)/arch/$(SRCARCH)/Makefile > -export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT > +export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT > > config: outputmakefile scripts_basic FORCE > $(Q)$(MAKE) $(build)=scripts/kconfig $@ > diff --git a/init/Kconfig b/init/Kconfig > index 2f974f412374..b0238c4b6e79 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1926,7 +1926,9 @@ config RUST > config RUSTC_VERSION_TEXT > string > depends on RUST > - default "$(shell,LC_ALL=C $(RUSTC) --version 2>/dev/null | head -n 1)" > + default "$(RUSTC_VERSION_TEXT)" > + help > + See `CC_VERSION_TEXT`. > > config BINDGEN_VERSION_TEXT > string > -- > 2.46.0 Do we already support rust in external kernel modules? In top-level Makefile's oot-kmod 'prepare' target we check that the compiler (version) is the same as when the kernel itself was built. If rust modules are supported, adding a similar check might be helpful. Nevertheless, Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
On Sat, Aug 17, 2024 at 2:58 PM Nicolas Schier <nicolas@fjasle.eu> wrote: > > If you send a v2, mind you consider reformatting so that this comment > block stays <= 80 chars? Sure. > Do we already support rust in external kernel modules? In top-level If you mean out-of-tree modules, then yeah, they should generally work (at least I test the build with a trivial one regularly, but perhaps it is missing something), although they are not the highest priority. > Makefile's oot-kmod 'prepare' target we check that the compiler > (version) is the same as when the kernel itself was built. If rust > modules are supported, adding a similar check might be helpful. That is a good point, I will take a look. > Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Thanks! Cheers, Miguel
© 2016 - 2026 Red Hat, Inc.