Messages in this thread Patch in this message | | | From | Andrea Righi <> | Subject | [PATCH v2] rust: allow to use INIT_STACK_ALL_ZERO | Date | Fri, 10 Feb 2023 22:51:41 +0100 |
| |
With CONFIG_INIT_STACK_ALL_ZERO enabled, bindgen passes -ftrivial-auto-var-init=zero to clang, that triggers the following error:
error: '-ftrivial-auto-var-init=zero' hasn't been enabled; enable it at your own peril for benchmarking purpose only with '-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang'
However, this additional option that is currently required by clang is going to be removed in the future (as the name of the option suggests), likely with clang-17.
So, make sure bindgen is using this extra option if the major version of the libclang used by bindgen is < 17.
In this way we can enable CONFIG_INIT_STACK_ALL_ZERO with CONFIG_RUST without triggering any build error.
Link: https://github.com/llvm/llvm-project/issues/44842 Signed-off-by: Andrea Righi <andrea.righi@canonical.com> ---
Changes in v2: - check the version of libclang used by bindgen to determine if we need to pass the additional clang option
rust/Makefile | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/rust/Makefile b/rust/Makefile index ff70c4c916f8..c77d7ce96a85 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -269,6 +269,19 @@ BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH)) # some configurations, with new GCC versions, etc. bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET) +# Auto variable zero-initialization requires an additional special option with +# clang that is going to be removed sometimes in the future (likely in +# clang-17), so make sure to pass this option only if clang supports it +# (libclang major version < 17). +# +# https://github.com/llvm/llvm-project/issues/44842 +ifdef CONFIG_INIT_STACK_ALL_ZERO +libclang_maj_ver=$(shell $(BINDGEN) $(srctree)/scripts/rust_is_available_bindgen_libclang.h 2>&1 | sed -ne 's/.*clang version \([0-9]*\).*/\1/p') +ifeq ($(shell expr $(libclang_maj_ver) \< 17), 1) +bindgen_extra_c_flags += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang +endif +endif + bindgen_c_flags = $(filter-out $(bindgen_skip_c_flags), $(c_flags)) \ $(bindgen_extra_c_flags) endif -- 2.38.1
| |