Now that `RUSTC_VERSION_TEXT` exists, use it to rebuild `core` when the version text changes (which in turn will trigger a rebuild of all the kernel Rust code). This also applies to proc macros (which only work with the `rustc` that compiled them), via the already existing dependency on `core.o`. That is cleaned up in the next commit. However, this does not cover host programs written in Rust, which is the same case in the C side. This is accomplished by referencing directly the generated file, instead of using the `fixdep` header trick, since we cannot change the Rust standard library sources. This is not too much of a burden, since it only needs to be done for `core`. Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> --- Masahiro: I used `$(objtree)` here since we still use it in the rest of this `Makefile`, but please let me know if you prefer otherwise. Thanks! rust/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/rust/Makefile b/rust/Makefile index 6c0644b6090c..966743a9ee25 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -370,7 +370,8 @@ $(obj)/core.o: private skip_clippy = 1 $(obj)/core.o: private skip_flags = -Wunreachable_pub $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym)) $(obj)/core.o: private rustc_target_flags = $(core-cfgs) -$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE +$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \ + $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE +$(call if_changed_dep,rustc_library) ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),) $(obj)/core.o: scripts/target.json -- 2.46.0