From e26fa546042add70944d018b930530d16b3cf626 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Sat, 17 Aug 2024 17:51:32 +0100 Subject: rust: kbuild: auto generate helper exports This removes the need to explicitly export all symbols. Generate helper exports similarly to what's currently done for Rust crates. These helpers are exclusively called from within Rust code and therefore can be treated similar as other Rust symbols. Signed-off-by: Gary Guo Reviewed-by: Boqun Feng Tested-by: Boqun Feng Link: https://lore.kernel.org/r/20240817165302.3852499-1-gary@garyguo.net [ Fixed dependency path, reworded slightly, edited comment a bit and rebased on top of the changes made when applying Andreas' patch (e.g. no `README.md` anymore, so moved the edits). - Miguel ] Signed-off-by: Miguel Ojeda --- rust/Makefile | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'rust/Makefile') diff --git a/rust/Makefile b/rust/Makefile index 99204e33f1dd..7ea5905f544c 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -16,8 +16,8 @@ no-clean-files += libmacros.so always-$(CONFIG_RUST) += bindings/bindings_generated.rs bindings/bindings_helpers_generated.rs obj-$(CONFIG_RUST) += alloc.o bindings.o kernel.o -always-$(CONFIG_RUST) += exports_alloc_generated.h exports_bindings_generated.h \ - exports_kernel_generated.h +always-$(CONFIG_RUST) += exports_alloc_generated.h exports_helpers_generated.h \ + exports_bindings_generated.h exports_kernel_generated.h always-$(CONFIG_RUST) += uapi/uapi_generated.rs obj-$(CONFIG_RUST) += uapi.o @@ -313,6 +313,18 @@ $(obj)/exports_core_generated.h: $(obj)/core.o FORCE $(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE $(call if_changed,exports) +# Even though Rust kernel modules should never use the bindings directly, +# symbols from the `bindings` crate and the C helpers need to be exported +# because Rust generics and inlined functions may not get their code generated +# in the crate where they are defined. Other helpers, called from non-inline +# functions, may not be exported, in principle. However, in general, the Rust +# compiler does not guarantee codegen will be performed for a non-inline +# function either. Therefore, we export all symbols from helpers and bindings. +# In the future, this may be revisited to reduce the number of exports after +# the compiler is informed about the places codegen is required. +$(obj)/exports_helpers_generated.h: $(obj)/helpers/helpers.o FORCE + $(call if_changed,exports) + $(obj)/exports_bindings_generated.h: $(obj)/bindings.o FORCE $(call if_changed,exports) -- cgit v1.2.3-73-gaa49b