# SPDX-License-Identifier: GPL-2.0 # Where to place rustdoc generated documentation rustdoc_output := $(objtree)/Documentation/output/rust/rustdoc obj-$(CONFIG_RUST) += core.o compiler_builtins.o always-$(CONFIG_RUST) += exports_core_generated.h # Missing prototypes are expected in the helpers since these are exported # for Rust only, thus there is no header nor prototypes. obj-$(CONFIG_RUST) += helpers.o CFLAGS_REMOVE_helpers.o = -Wmissing-prototypes -Wmissing-declarations always-$(CONFIG_RUST) += libmacros.so no-clean-files += libmacros.so always-$(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-$(CONFIG_RUST) += uapi/uapi_generated.rs obj-$(CONFIG_RUST) += uapi.o ifdef CONFIG_RUST_BUILD_ASSERT_ALLOW obj-$(CONFIG_RUST) += build_error.o else always-$(CONFIG_RUST) += build_error.o endif obj-$(CONFIG_RUST) += exports.o always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.rs always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.c obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.o obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.o # Avoids running `$(RUSTC)` for the sysroot when it may not be available. ifdef CONFIG_RUST # `$(rust_flags)` is passed in case the user added `--sysroot`. rustc_sysroot := $(shell MAKEFLAGS= $(RUSTC) $(rust_flags) --print sysroot) rustc_host_target := $(shell $(RUSTC) --version --verbose | grep -F 'host: ' | cut -d' ' -f2) RUST_LIB_SRC ?= $(rustc_sysroot)/lib/rustlib/src/rust/library ifeq ($(quiet),silent_) cargo_quiet=-q rust_test_quiet=-q rustdoc_test_quiet=--test-args -q rustdoc_test_kernel_quiet=>/dev/null else ifeq ($(quiet),quiet_) rust_test_quiet=-q rustdoc_test_quiet=--test-args -q rustdoc_test_kernel_quiet=>/dev/null else cargo_quiet=--verbose endif core-cfgs = \ --cfg no_fp_fmt_parse alloc-cfgs = \ --cfg no_borrow \ --cfg no_fmt \ --cfg no_global_oom_handling \ --cfg no_macros \ --cfg no_rc \ --cfg no_str \ --cfg no_string \ --cfg no_sync \ --cfg no_thin quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $< cmd_rustdoc = \ OBJTREE=$(abspath $(objtree)) \ $(RUSTDOC) $(if $(rustdoc_host),$(rust_common_flags),$(rust_flags)) \ $(rustc_target_flags) -L$(objtree)/$(obj) \ --output $(rustdoc_output) \ --crate-name $(subst rustdoc-,,$@) \ $(if $(rustdoc_host),,--sysroot=/dev/null) \ @$(objtree)/include/generated/rustc_cfg $< # The `html_logo_url` and `html_favicon_url` forms of the `doc` attribute # can be used to specify a custom logo. However: # - The given value is used as-is, thus it cannot be relative or a local file # (unlike the non-custom case) since the generated docs have subfolders. # - It requires adding it to every crate. # - It requires changing `core` which comes from the sysroot. # # Using `-Zcrate-attr` would solve the last two points, but not the first. # The https://github.com/rust-lang/rfcs/pull/3226 RFC suggests two new # command-like flags to solve the issue. Meanwhile, we use the non-custom case # and then retouch the generated files. rustdoc: rustdoc-core rustdoc-macros rustdoc-compiler_builtins \ rustdoc-alloc rustdoc-kernel $(Q)cp $(srctree)/Documentation/images/logo.svg $(rustdoc_output)/static.files/ $(Q)cp $(srctree)/Documentation/images/COPYING-logo $(rustdoc_output)/static.files/ $(Q)find $(rustdoc_output) -name '*.html' -type f -print0 | xargs -0 sed -Ei \ -e 's:rust-logo-[0-9a-f]+\.svg:logo.svg:g' \ -e 's:favicon-[0-9a-f]+\.svg:logo.svg:g' \ -e 's:::g' \ -e 's:::g' $(Q)for f in $(rustdoc_output)/static.files/rustdoc-*.css; do \ echo ".logo-container > img { object-fit: contain; }" >> $$f; done rustdoc-macros: private rustdoc_host = yes rustdoc-macros: private rustc_target_flags = --crate-type proc-macro \ --extern proc_macro rustdoc-macros: $(src)/macros/lib.rs FORCE +$(call if_changed,rustdoc) rustdoc-core: private rustc_target_flags = $(core-cfgs) rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE +$(call if_changed,rustdoc) rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE +$(call if_changed,rustdoc) # We need to allow `rustdoc::broken_intra_doc_links` because some # `no_global_oom_handling` functions refer to non-`no_global_oom_handling` # functions. Ideally `rustdoc` would have a way to distinguish broken links # due to things that are "configured out" vs. entirely non-existing ones. rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \ -Arustdoc::broken_intra_doc_links rustdoc-alloc: $(src)/alloc/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE +$(call if_changed,rustdoc) rustdoc-kernel: private rustc_target_flags = --extern alloc \ --extern build_error --extern macros=$(objtree)/$(obj)/libmacros.so \ --extern bindings --extern uapi rustdoc-kernel: $(src)/kernel/lib.rs rustdoc-core rustdoc-macros \ rustdoc-compiler_builtins rustdoc-alloc $(obj)/libmacros.so \ $(obj)/bindings.o FORCE +$(call if_changed,rustdoc) quiet_cmd_rustc_test_library = RUSTC TL $< cmd_rustc_test_library = \ OBJTREE=$(abspath $(objtree)) \ $(RUSTC) $(rust_common_flags) \ @$(objtree)/include/generated/rustc_cfg $(rustc_target_flags) \ --crate-type $(if $(rustc_test_library_proc),proc-macro,rlib) \ --out-dir $(objtree)/$(obj)/test --cfg testlib \ --sysroot $(objtree)/$(obj)/test/sysroot \ -L$(objtree)/$(obj)/test \ --crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $< rusttestlib-build_error: $(src)/build_error.rs rusttest-prepare FORCE +$(call if_changed,rustc_test_library) rusttestlib-macros: private rustc_target_flags = --extern proc_macro rusttestlib-macros: private rustc_test_library_proc = yes rusttestlib-macros: $(src)/macros/lib.rs rusttest-prepare FORCE +$(call if_changed,rustc_test_library) rusttestlib-bindings: $(src)/bindings/lib.rs rusttest-prepare FORCE +$(call if_changed,rustc_test_library) rusttestlib-uapi: $(src)/uapi/lib.rs rusttest-prepare FORCE +$(call if_changed,rustc_test_library) quiet_cmd_rustdoc_test = RUSTDOC T $< cmd_rustdoc_test = \ OBJTREE=$(abspath $(objtree)) \ $(RUSTDOC) --test $(rust_common_flags) \ @$(objtree)/include/generated/rustc_cfg \ $(rustc_target_flags) $(rustdoc_test_target_flags) \ --sysroot $(objtree)/$(obj)/test/sysroot $(rustdoc_test_quiet) \ -L$(objtree)/$(obj)/test --output $(rustdoc_output) \ --crate-name $(subst rusttest-,,$@) $< quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $< cmd_rustdoc_test_kernel = \ rm -rf $(objtree)/$(obj)/test/doctests/kernel; \ mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \ OBJTREE=$(abspath $(objtree)) \ $(RUSTDOC) --test $(rust_flags) \ @$(objtree)/include/generated/rustc_cfg \ -L$(objtree)/$(obj) --extern alloc --extern kernel \ --extern build_error --extern macros \ --extern bindings --extern uapi \ --no-run --crate-name kernel -Zunstable-options \ --sysroot=/dev/null \ --test-builder $(objtree)/scripts/rustdoc_test_builder \ $< $(rustdoc_test_kernel_quiet); \ $(objtree)/scripts/rustdoc_test_gen %/doctests_kernel_generated.rs %/doctests_kernel_generated_kunit.c: \ $(src)/kernel/lib.rs $(obj)/kernel.o \ $(objtree)/scripts/rustdoc_test_builder \ $(objtree)/scripts/rustdoc_test_gen FORCE +$(call if_changed,rustdoc_test_kernel) # We cannot use `-Zpanic-abort-tests` because some tests are dynamic, # so for the moment we skip `-Cpanic=abort`. quiet_cmd_rustc_test = RUSTC T $< cmd_rustc_test = \ OBJTREE=$(abspath $(objtree)) \ $(RUSTC) --test $(rust_common_flags) \ @$(objtree)/include/generated/rustc_cfg \ $(rustc_target_flags) --out-dir $(objtree)/$(obj)/test \ --sysroot $(objtree)/$(obj)/test/sysroot \ -L$(objtree)/$(obj)/test \ --crate-name $(subst rusttest-,,$@) $<; \ $(objtree)/$(obj)/test/$(subst rusttest-,,$@) $(rust_test_quiet) \ $(rustc_test_run_flags) rusttest: rusttest-macros rusttest-kernel # This prepares a custom sysroot with our custom `alloc` instead of # the standard one. # # This requires several hacks: # - Unlike `core` and `alloc`, `std` depends on more than a dozen crates, # including third-party crates that need to be downloaded, plus custom # `build.rs` steps. Thus hardcoding things here is not maintainable. # - `cargo` knows how to build the standard library, but it is an unstable # feature so far (`-Zbuild-std`). # - `cargo` only considers the use case of building the standard library # to use it in a given package. Thus we need to create a dummy package # and pick the generated libraries from there. # - Since we only keep a subset of upstream `alloc` in-tree, we need # to recreate it on the fly by putting our sources on top. # - The usual ways of modifying the dependency graph in `cargo` do not seem # to apply for the `-Zbuild-std` steps, thus we have to mislead it # by modifying the sources in the sysroot. # - To avoid messing with the user's Rust installation, we create a clone # of the sysroot. However, `cargo` ignores `RUSTFLAGS` in the `-Zbuild-std` # steps, thus we use a wrapper binary passed via `RUSTC` to pass the flag. # # In the future, we hope to avoid the whole ordeal by either: # - Making the `test` crate not depend on `std` (either improving upstream # or having our own custom crate). # - Making the tests run in kernel space (requires the previous point). # - Making `std` and friends be more like a "normal" crate, so that # `-Zbuild-std` and related hacks are not needed. quiet_cmd_rustsysroot = RUSTSYSROOT cmd_rustsysroot = \ rm -rf $(objtree)/$(obj)/test; \ mkdir -p $(objtree)/$(obj)/test; \ cp -a $(rustc_sysroot) $(objtree)/$(obj)/test/sysroot; \ cp -r $(src)/alloc/* \ $(objtree)/$(obj)/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \ echo '\#!/bin/sh' > $(objtree)/$(obj)/test/rustc_sysroot; \ echo "$(RUSTC) --sysroot=$(abspath $(objtree)/$(obj)/test/sysroot) \"\$$@\"" \ >> $(objtree)/$(obj)/test/rustc_sysroot; \ chmod u+x $(objtree)/$(obj)/test/rustc_sysroot; \ $(CARGO) -q new $(objtree)/$(obj)/test/dummy; \ RUSTC=$(objtree)/$(obj)/test/rustc_sysroot $(CARGO) $(cargo_quiet) \ test -Zbuild-std --target $(rustc_host_target) \ --manifest-path $(objtree)/$(obj)/test/dummy/Cargo.toml; \ rm $(objtree)/$(obj)/test/sysroot/lib/rustlib/$(rustc_host_target)/lib/*; \ cp $(objtree)/$(obj)/test/dummy/target/$(rustc_host_target)/debug/deps/* \ $(objtree)/$(obj)/test/sysroot/lib/rustlib/$(rustc_host_target)/lib rusttest-prepare: FORCE +$(call if_changed,rustsysroot) rusttest-macros: private rustc_target_flags = --extern proc_macro rusttest-macros: private rustdoc_test_target_flags = --crate-type proc-macro rusttest-macros: $(src)/macros/lib.rs rusttest-prepare FORCE +$(call if_changed,rustc_test) +$(call if_changed,rustdoc_test) rusttest-kernel: private rustc_target_flags = --extern alloc \ --extern build_error --extern macros --extern bindings --extern uapi rusttest-kernel: $(src)/kernel/lib.rs rusttest-prepare \ rusttestlib-build_error rusttestlib-macros rusttestlib-bindings \ rusttestlib-uapi FORCE +$(call if_changed,rustc_test) +$(call if_changed,rustc_test_library) ifdef CONFIG_CC_IS_CLANG bindgen_c_flags = $(c_flags) else # bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC # plugin backend and/or the Clang driver would be perfectly compatible with GCC. # # For the moment, here we are tweaking the flags on the fly. This is a hack, # and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT` # if we end up using one of those structs). bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \ -mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \ -mindirect-branch=thunk-extern -mindirect-branch-register \ -mfunction-return=thunk-extern -mrecord-mcount -mabi=lp64 \ -mindirect-branch-cs-prefix -mstack-protector-guard% -mtraceback=no \ -mno-pointers-to-nested-functions -mno-string \ -mno-strict-align -mstrict-align \ -fconserve-stack -falign-jumps=% -falign-loops=% \ -femit-struct-debug-baseonly -fno-ipa-cp-clone -fno-ipa-sra \ -fno-partial-inlining -fplugin-arg-arm_ssp_per_task_plugin-% \ -fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \ -fzero-call-used-regs=% -fno-stack-clash-protection \ -fno-inline-functions-called-once -fsanitize=bounds-strict \ -fstrict-flex-arrays=% \ --param=% --param asan-% # Derived from `scripts/Makefile.clang`. BINDGEN_TARGET_x86 := x86_64-linux-gnu BINDGEN_TARGET_arm64 := aarch64-linux-gnu BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH)) # All warnings are inhibited since GCC builds are very experimental, # many GCC warnings are not supported by Clang, they may only appear in # some configurations, with new GCC versions, etc. bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET) # Auto variable zero-initialization requires an additional special option with # clang that is going to be removed sometime in the future (likely in # clang-18), so make sure to pass this option only if clang supports it # (libclang major version < 16). # # https://github.com/llvm/llvm-project/issues/44842 # https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags ifdef CONFIG_INIT_STACK_ALL_ZERO libclang_maj_ver=$(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) \< 16), 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 ifdef CONFIG_LTO bindgen_c_flags_lto = $(filter-out $(CC_FLAGS_LTO), $(bindgen_c_flags)) else bindgen_c_flags_lto = $(bindgen_c_flags) endif bindgen_c_flags_final = $(bindgen_c_flags_lto) -D__BINDGEN__ quiet_cmd_bindgen = BINDGEN $@ cmd_bindgen = \ $(BINDGEN) $< $(bindgen_target_flags) \ --use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \ --no-debug '.*' \ -o $@ -- $(bindgen_c_flags_final) -DMODULE \ $(bindgen_target_cflags) $(bindgen_target_extra) $(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \ $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters) $(obj)/bindings/bindings_generated.rs: private bindgen_target_extra = ; \ sed -Ei 's/pub const RUST_CONST_HELPER_([a-zA-Z0-9_]*)/pub const \1/g' $@ $(obj)/bindings/bindings_generated.rs: $(src)/bindings/bindings_helper.h \ $(src)/bindgen_parameters FORCE $(call if_changed_dep,bindgen) $(obj)/uapi/uapi_generated.rs: private bindgen_target_flags = \ $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters) $(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \ $(src)/bindgen_parameters FORCE $(call if_changed_dep,bindgen) # See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn # with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here # given it is `libclang`; but for consistency, future Clang changes and/or # a potential future GCC backend for `bindgen`, we disable it too. $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \ --blocklist-type '.*' --allowlist-var '' \ --allowlist-function 'rust_helper_.*' $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \ -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \ sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n pub fn \1/g' $@ $(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers.c FORCE $(call if_changed_dep,bindgen) quiet_cmd_exports = EXPORTS $@ cmd_exports = \ $(NM) -p --defined-only $< \ | awk '/ (T|R|D) / {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$3}' > $@ $(obj)/exports_core_generated.h: $(obj)/core.o FORCE $(call if_changed,exports) $(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE $(call if_changed,exports) $(obj)/exports_bindings_generated.h: $(obj)/bindings.o FORCE $(call if_changed,exports) $(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE $(call if_changed,exports) quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@ cmd_rustc_procmacro = \ $(RUSTC_OR_CLIPPY) $(rust_common_flags) \ -Clinker-flavor=gcc -Clinker=$(HOSTCC) \ -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \ --emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \ --crate-type proc-macro \ --crate-name $(patsubst lib%.so,%,$(notdir $@)) $< # Procedural macros can only be used with the `rustc` that compiled it. # Therefore, to get `libmacros.so` automatically recompiled when the compiler # version changes, we add `core.o` as a dependency (even if it is not needed). $(obj)/libmacros.so: $(src)/macros/lib.rs $(obj)/core.o FORCE +$(call if_changed_dep,rustc_procmacro) quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@ cmd_rustc_library = \ OBJTREE=$(abspath $(objtree)) \ $(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \ $(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \ --emit=dep-info=$(depfile) --emit=obj=$@ \ --emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \ --crate-type rlib -L$(objtree)/$(obj) \ --crate-name $(patsubst %.o,%,$(notdir $@)) $< \ --sysroot=/dev/null \ $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@) rust-analyzer: $(Q)$(srctree)/scripts/generate_rust_analyzer.py \ --cfgs='core=$(core-cfgs)' --cfgs='alloc=$(alloc-cfgs)' \ $(realpath $(srctree)) $(realpath $(objtree)) \ $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \ $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json redirect-intrinsics = \ __addsf3 __eqsf2 __gesf2 __lesf2 __ltsf2 __mulsf3 __nesf2 __unordsf2 \ __adddf3 __ledf2 __ltdf2 __muldf3 __unorddf2 \ __muloti4 __multi3 \ __udivmodti4 __udivti3 __umodti3 ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),) # These intrinsics are defined for ARM64 and RISCV64 redirect-intrinsics += \ __ashrti3 \ __ashlti3 __lshrti3 endif $(obj)/core.o: private skip_clippy = 1 $(obj)/core.o: private skip_flags = -Dunreachable_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: $(RUST_LIB_SRC)/core/src/lib.rs FORCE +$(call if_changed_dep,rustc_library) ifneq ($(or $(CONFIG_X86_64),$(CONFIG_LOONGARCH)),) $(obj)/core.o: scripts/target.json endif $(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*' $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE +$(call if_changed_dep,rustc_library) $(obj)/alloc.o: private skip_clippy = 1 $(obj)/alloc.o: private skip_flags = -Dunreachable_pub $(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs) $(obj)/alloc.o: $(src)/alloc/lib.rs $(obj)/compiler_builtins.o FORCE +$(call if_changed_dep,rustc_library) $(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE +$(call if_changed_dep,rustc_library) $(obj)/bindings.o: $(src)/bindings/lib.rs \ $(obj)/compiler_builtins.o \ $(obj)/bindings/bindings_generated.rs \ $(obj)/bindings/bindings_helpers_generated.rs FORCE +$(call if_changed_dep,rustc_library) $(obj)/uapi.o: $(src)/uapi/lib.rs \ $(obj)/compiler_builtins.o \ $(obj)/uapi/uapi_generated.rs FORCE +$(call if_changed_dep,rustc_library) $(obj)/kernel.o: private rustc_target_flags = --extern alloc \ --extern build_error --extern macros --extern bindings --extern uapi $(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \ $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE +$(call if_changed_dep,rustc_library) endif # CONFIG_RUST