1# SPDX-License-Identifier: GPL-2.0 2 3# Where to place rustdoc generated documentation 4rustdoc_output := $(objtree)/Documentation/output/rust/rustdoc 5 6obj-$(CONFIG_RUST) += core.o compiler_builtins.o 7always-$(CONFIG_RUST) += exports_core_generated.h 8 9# Missing prototypes are expected in the helpers since these are exported 10# for Rust only, thus there is no header nor prototypes. 11obj-$(CONFIG_RUST) += helpers/helpers.o 12CFLAGS_REMOVE_helpers/helpers.o = -Wmissing-prototypes -Wmissing-declarations 13 14always-$(CONFIG_RUST) += libmacros.so 15no-clean-files += libmacros.so 16 17always-$(CONFIG_RUST) += bindings/bindings_generated.rs bindings/bindings_helpers_generated.rs 18obj-$(CONFIG_RUST) += alloc.o bindings.o kernel.o 19always-$(CONFIG_RUST) += exports_alloc_generated.h exports_helpers_generated.h \ 20 exports_bindings_generated.h exports_kernel_generated.h 21 22always-$(CONFIG_RUST) += uapi/uapi_generated.rs 23obj-$(CONFIG_RUST) += uapi.o 24 25ifdef CONFIG_RUST_BUILD_ASSERT_ALLOW 26obj-$(CONFIG_RUST) += build_error.o 27else 28always-$(CONFIG_RUST) += build_error.o 29endif 30 31obj-$(CONFIG_RUST) += exports.o 32 33always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.rs 34always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.c 35 36obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.o 37obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.o 38 39# Avoids running `$(RUSTC)` for the sysroot when it may not be available. 40ifdef CONFIG_RUST 41 42# `$(rust_flags)` is passed in case the user added `--sysroot`. 43rustc_sysroot := $(shell MAKEFLAGS= $(RUSTC) $(rust_flags) --print sysroot) 44rustc_host_target := $(shell $(RUSTC) --version --verbose | grep -F 'host: ' | cut -d' ' -f2) 45RUST_LIB_SRC ?= $(rustc_sysroot)/lib/rustlib/src/rust/library 46 47ifneq ($(quiet),) 48rust_test_quiet=-q 49rustdoc_test_quiet=--test-args -q 50rustdoc_test_kernel_quiet=>/dev/null 51endif 52 53core-cfgs = \ 54 --cfg no_fp_fmt_parse 55 56alloc-cfgs = \ 57 --cfg no_global_oom_handling \ 58 --cfg no_rc \ 59 --cfg no_sync 60 61quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $< 62 cmd_rustdoc = \ 63 OBJTREE=$(abspath $(objtree)) \ 64 $(RUSTDOC) $(filter-out $(skip_flags),$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \ 65 $(rustc_target_flags) -L$(objtree)/$(obj) \ 66 -Zunstable-options --generate-link-to-definition \ 67 --output $(rustdoc_output) \ 68 --crate-name $(subst rustdoc-,,$@) \ 69 $(if $(rustdoc_host),,--sysroot=/dev/null) \ 70 @$(objtree)/include/generated/rustc_cfg $< 71 72# The `html_logo_url` and `html_favicon_url` forms of the `doc` attribute 73# can be used to specify a custom logo. However: 74# - The given value is used as-is, thus it cannot be relative or a local file 75# (unlike the non-custom case) since the generated docs have subfolders. 76# - It requires adding it to every crate. 77# - It requires changing `core` which comes from the sysroot. 78# 79# Using `-Zcrate-attr` would solve the last two points, but not the first. 80# The https://github.com/rust-lang/rfcs/pull/3226 RFC suggests two new 81# command-like flags to solve the issue. Meanwhile, we use the non-custom case 82# and then retouch the generated files. 83rustdoc: rustdoc-core rustdoc-macros rustdoc-compiler_builtins \ 84 rustdoc-alloc rustdoc-kernel 85 $(Q)cp $(srctree)/Documentation/images/logo.svg $(rustdoc_output)/static.files/ 86 $(Q)cp $(srctree)/Documentation/images/COPYING-logo $(rustdoc_output)/static.files/ 87 $(Q)find $(rustdoc_output) -name '*.html' -type f -print0 | xargs -0 sed -Ei \ 88 -e 's:rust-logo-[0-9a-f]+\.svg:logo.svg:g' \ 89 -e 's:favicon-[0-9a-f]+\.svg:logo.svg:g' \ 90 -e 's:<link rel="alternate icon" type="image/png" href="[/.]+/static\.files/favicon-(16x16|32x32)-[0-9a-f]+\.png">::g' \ 91 -e 's:<a href="srctree/([^"]+)">:<a href="$(realpath $(srctree))/\1">:g' 92 $(Q)for f in $(rustdoc_output)/static.files/rustdoc-*.css; do \ 93 echo ".logo-container > img { object-fit: contain; }" >> $$f; done 94 95rustdoc-macros: private rustdoc_host = yes 96rustdoc-macros: private rustc_target_flags = --crate-type proc-macro \ 97 --extern proc_macro 98rustdoc-macros: $(src)/macros/lib.rs FORCE 99 +$(call if_changed,rustdoc) 100 101# Starting with Rust 1.82.0, skipping `-Wrustdoc::unescaped_backticks` should 102# not be needed -- see https://github.com/rust-lang/rust/pull/128307. 103rustdoc-core: private skip_flags = -Wrustdoc::unescaped_backticks 104rustdoc-core: private rustc_target_flags = $(core-cfgs) 105rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE 106 +$(call if_changed,rustdoc) 107 108rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE 109 +$(call if_changed,rustdoc) 110 111# We need to allow `rustdoc::broken_intra_doc_links` because some 112# `no_global_oom_handling` functions refer to non-`no_global_oom_handling` 113# functions. Ideally `rustdoc` would have a way to distinguish broken links 114# due to things that are "configured out" vs. entirely non-existing ones. 115rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \ 116 -Arustdoc::broken_intra_doc_links 117rustdoc-alloc: $(RUST_LIB_SRC)/alloc/src/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE 118 +$(call if_changed,rustdoc) 119 120rustdoc-kernel: private rustc_target_flags = --extern alloc \ 121 --extern build_error --extern macros=$(objtree)/$(obj)/libmacros.so \ 122 --extern bindings --extern uapi 123rustdoc-kernel: $(src)/kernel/lib.rs rustdoc-core rustdoc-macros \ 124 rustdoc-compiler_builtins rustdoc-alloc $(obj)/libmacros.so \ 125 $(obj)/bindings.o FORCE 126 +$(call if_changed,rustdoc) 127 128quiet_cmd_rustc_test_library = RUSTC TL $< 129 cmd_rustc_test_library = \ 130 OBJTREE=$(abspath $(objtree)) \ 131 $(RUSTC) $(rust_common_flags) \ 132 @$(objtree)/include/generated/rustc_cfg $(rustc_target_flags) \ 133 --crate-type $(if $(rustc_test_library_proc),proc-macro,rlib) \ 134 --out-dir $(objtree)/$(obj)/test --cfg testlib \ 135 -L$(objtree)/$(obj)/test \ 136 --crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $< 137 138rusttestlib-build_error: $(src)/build_error.rs FORCE 139 +$(call if_changed,rustc_test_library) 140 141rusttestlib-macros: private rustc_target_flags = --extern proc_macro 142rusttestlib-macros: private rustc_test_library_proc = yes 143rusttestlib-macros: $(src)/macros/lib.rs FORCE 144 +$(call if_changed,rustc_test_library) 145 146rusttestlib-bindings: $(src)/bindings/lib.rs FORCE 147 +$(call if_changed,rustc_test_library) 148 149rusttestlib-uapi: $(src)/uapi/lib.rs FORCE 150 +$(call if_changed,rustc_test_library) 151 152quiet_cmd_rustdoc_test = RUSTDOC T $< 153 cmd_rustdoc_test = \ 154 OBJTREE=$(abspath $(objtree)) \ 155 $(RUSTDOC) --test $(rust_common_flags) \ 156 @$(objtree)/include/generated/rustc_cfg \ 157 $(rustc_target_flags) $(rustdoc_test_target_flags) \ 158 $(rustdoc_test_quiet) \ 159 -L$(objtree)/$(obj)/test --output $(rustdoc_output) \ 160 --crate-name $(subst rusttest-,,$@) $< 161 162quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $< 163 cmd_rustdoc_test_kernel = \ 164 rm -rf $(objtree)/$(obj)/test/doctests/kernel; \ 165 mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \ 166 OBJTREE=$(abspath $(objtree)) \ 167 $(RUSTDOC) --test $(rust_flags) \ 168 -L$(objtree)/$(obj) --extern alloc --extern kernel \ 169 --extern build_error --extern macros \ 170 --extern bindings --extern uapi \ 171 --no-run --crate-name kernel -Zunstable-options \ 172 --sysroot=/dev/null \ 173 --test-builder $(objtree)/scripts/rustdoc_test_builder \ 174 $< $(rustdoc_test_kernel_quiet); \ 175 $(objtree)/scripts/rustdoc_test_gen 176 177%/doctests_kernel_generated.rs %/doctests_kernel_generated_kunit.c: \ 178 $(src)/kernel/lib.rs $(obj)/kernel.o \ 179 $(objtree)/scripts/rustdoc_test_builder \ 180 $(objtree)/scripts/rustdoc_test_gen FORCE 181 +$(call if_changed,rustdoc_test_kernel) 182 183# We cannot use `-Zpanic-abort-tests` because some tests are dynamic, 184# so for the moment we skip `-Cpanic=abort`. 185quiet_cmd_rustc_test = RUSTC T $< 186 cmd_rustc_test = \ 187 OBJTREE=$(abspath $(objtree)) \ 188 $(RUSTC) --test $(rust_common_flags) \ 189 @$(objtree)/include/generated/rustc_cfg \ 190 $(rustc_target_flags) --out-dir $(objtree)/$(obj)/test \ 191 -L$(objtree)/$(obj)/test \ 192 --crate-name $(subst rusttest-,,$@) $<; \ 193 $(objtree)/$(obj)/test/$(subst rusttest-,,$@) $(rust_test_quiet) \ 194 $(rustc_test_run_flags) 195 196rusttest: rusttest-macros rusttest-kernel 197 198rusttest-macros: private rustc_target_flags = --extern proc_macro 199rusttest-macros: private rustdoc_test_target_flags = --crate-type proc-macro 200rusttest-macros: $(src)/macros/lib.rs FORCE 201 +$(call if_changed,rustc_test) 202 +$(call if_changed,rustdoc_test) 203 204rusttest-kernel: private rustc_target_flags = --extern alloc \ 205 --extern build_error --extern macros --extern bindings --extern uapi 206rusttest-kernel: $(src)/kernel/lib.rs \ 207 rusttestlib-build_error rusttestlib-macros rusttestlib-bindings \ 208 rusttestlib-uapi FORCE 209 +$(call if_changed,rustc_test) 210 +$(call if_changed,rustc_test_library) 211 212ifdef CONFIG_CC_IS_CLANG 213bindgen_c_flags = $(c_flags) 214else 215# bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC 216# plugin backend and/or the Clang driver would be perfectly compatible with GCC. 217# 218# For the moment, here we are tweaking the flags on the fly. This is a hack, 219# and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT` 220# if we end up using one of those structs). 221bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \ 222 -mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \ 223 -mindirect-branch=thunk-extern -mindirect-branch-register \ 224 -mfunction-return=thunk-extern -mrecord-mcount -mabi=lp64 \ 225 -mindirect-branch-cs-prefix -mstack-protector-guard% -mtraceback=no \ 226 -mno-pointers-to-nested-functions -mno-string \ 227 -mno-strict-align -mstrict-align \ 228 -fconserve-stack -falign-jumps=% -falign-loops=% \ 229 -femit-struct-debug-baseonly -fno-ipa-cp-clone -fno-ipa-sra \ 230 -fno-partial-inlining -fplugin-arg-arm_ssp_per_task_plugin-% \ 231 -fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \ 232 -fzero-call-used-regs=% -fno-stack-clash-protection \ 233 -fno-inline-functions-called-once -fsanitize=bounds-strict \ 234 -fstrict-flex-arrays=% -fmin-function-alignment=% \ 235 --param=% --param asan-% 236 237# Derived from `scripts/Makefile.clang`. 238BINDGEN_TARGET_x86 := x86_64-linux-gnu 239BINDGEN_TARGET_arm64 := aarch64-linux-gnu 240BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH)) 241 242# All warnings are inhibited since GCC builds are very experimental, 243# many GCC warnings are not supported by Clang, they may only appear in 244# some configurations, with new GCC versions, etc. 245bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET) 246 247# Auto variable zero-initialization requires an additional special option with 248# clang that is going to be removed sometime in the future (likely in 249# clang-18), so make sure to pass this option only if clang supports it 250# (libclang major version < 16). 251# 252# https://github.com/llvm/llvm-project/issues/44842 253# https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags 254ifdef CONFIG_INIT_STACK_ALL_ZERO 255libclang_maj_ver=$(shell $(BINDGEN) $(srctree)/scripts/rust_is_available_bindgen_libclang.h 2>&1 | sed -ne 's/.*clang version \([0-9]*\).*/\1/p') 256ifeq ($(shell expr $(libclang_maj_ver) \< 16), 1) 257bindgen_extra_c_flags += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang 258endif 259endif 260 261bindgen_c_flags = $(filter-out $(bindgen_skip_c_flags), $(c_flags)) \ 262 $(bindgen_extra_c_flags) 263endif 264 265ifdef CONFIG_LTO 266bindgen_c_flags_lto = $(filter-out $(CC_FLAGS_LTO), $(bindgen_c_flags)) 267else 268bindgen_c_flags_lto = $(bindgen_c_flags) 269endif 270 271bindgen_c_flags_final = $(bindgen_c_flags_lto) -D__BINDGEN__ 272 273quiet_cmd_bindgen = BINDGEN $@ 274 cmd_bindgen = \ 275 $(BINDGEN) $< $(bindgen_target_flags) \ 276 --use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \ 277 --no-debug '.*' --enable-function-attribute-detection \ 278 -o $@ -- $(bindgen_c_flags_final) -DMODULE \ 279 $(bindgen_target_cflags) $(bindgen_target_extra) 280 281$(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \ 282 $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters) 283$(obj)/bindings/bindings_generated.rs: private bindgen_target_extra = ; \ 284 sed -Ei 's/pub const RUST_CONST_HELPER_([a-zA-Z0-9_]*)/pub const \1/g' $@ 285$(obj)/bindings/bindings_generated.rs: $(src)/bindings/bindings_helper.h \ 286 $(src)/bindgen_parameters FORCE 287 $(call if_changed_dep,bindgen) 288 289$(obj)/uapi/uapi_generated.rs: private bindgen_target_flags = \ 290 $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters) 291$(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \ 292 $(src)/bindgen_parameters FORCE 293 $(call if_changed_dep,bindgen) 294 295# See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn 296# with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here 297# given it is `libclang`; but for consistency, future Clang changes and/or 298# a potential future GCC backend for `bindgen`, we disable it too. 299$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \ 300 --blocklist-type '.*' --allowlist-var '' \ 301 --allowlist-function 'rust_helper_.*' 302$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \ 303 -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations 304$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \ 305 sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n pub fn \1/g' $@ 306$(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers/helpers.c FORCE 307 $(call if_changed_dep,bindgen) 308 309quiet_cmd_exports = EXPORTS $@ 310 cmd_exports = \ 311 $(NM) -p --defined-only $< \ 312 | awk '$$2~/(T|R|D|B)/ && $$3!~/__cfi/ {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$3}' > $@ 313 314$(obj)/exports_core_generated.h: $(obj)/core.o FORCE 315 $(call if_changed,exports) 316 317$(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE 318 $(call if_changed,exports) 319 320# Even though Rust kernel modules should never use the bindings directly, 321# symbols from the `bindings` crate and the C helpers need to be exported 322# because Rust generics and inlined functions may not get their code generated 323# in the crate where they are defined. Other helpers, called from non-inline 324# functions, may not be exported, in principle. However, in general, the Rust 325# compiler does not guarantee codegen will be performed for a non-inline 326# function either. Therefore, we export all symbols from helpers and bindings. 327# In the future, this may be revisited to reduce the number of exports after 328# the compiler is informed about the places codegen is required. 329$(obj)/exports_helpers_generated.h: $(obj)/helpers/helpers.o FORCE 330 $(call if_changed,exports) 331 332$(obj)/exports_bindings_generated.h: $(obj)/bindings.o FORCE 333 $(call if_changed,exports) 334 335$(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE 336 $(call if_changed,exports) 337 338quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@ 339 cmd_rustc_procmacro = \ 340 $(RUSTC_OR_CLIPPY) $(rust_common_flags) \ 341 -Clinker-flavor=gcc -Clinker=$(HOSTCC) \ 342 -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \ 343 --emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \ 344 --crate-type proc-macro \ 345 --crate-name $(patsubst lib%.so,%,$(notdir $@)) $< 346 347# Procedural macros can only be used with the `rustc` that compiled it. 348$(obj)/libmacros.so: $(src)/macros/lib.rs FORCE 349 +$(call if_changed_dep,rustc_procmacro) 350 351quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@ 352 cmd_rustc_library = \ 353 OBJTREE=$(abspath $(objtree)) \ 354 $(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \ 355 $(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \ 356 --emit=dep-info=$(depfile) --emit=obj=$@ \ 357 --emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \ 358 --crate-type rlib -L$(objtree)/$(obj) \ 359 --crate-name $(patsubst %.o,%,$(notdir $@)) $< \ 360 --sysroot=/dev/null \ 361 $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@) \ 362 $(cmd_objtool) 363 364rust-analyzer: 365 $(Q)$(srctree)/scripts/generate_rust_analyzer.py \ 366 --cfgs='core=$(core-cfgs)' --cfgs='alloc=$(alloc-cfgs)' \ 367 $(realpath $(srctree)) $(realpath $(objtree)) \ 368 $(rustc_sysroot) $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \ 369 $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json 370 371redirect-intrinsics = \ 372 __addsf3 __eqsf2 __extendsfdf2 __gesf2 __lesf2 __ltsf2 __mulsf3 __nesf2 __truncdfsf2 __unordsf2 \ 373 __adddf3 __eqdf2 __ledf2 __ltdf2 __muldf3 __unorddf2 \ 374 __muloti4 __multi3 \ 375 __udivmodti4 __udivti3 __umodti3 376 377ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),) 378 # These intrinsics are defined for ARM64 and RISCV64 379 redirect-intrinsics += \ 380 __ashrti3 \ 381 __ashlti3 __lshrti3 382endif 383 384define rule_rustc_library 385 $(call cmd_and_fixdep,rustc_library) 386 $(call cmd,gen_objtooldep) 387endef 388 389$(obj)/core.o: private skip_clippy = 1 390$(obj)/core.o: private skip_flags = -Wunreachable_pub 391$(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym)) 392$(obj)/core.o: private rustc_target_flags = $(core-cfgs) 393$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \ 394 $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE 395 +$(call if_changed_rule,rustc_library) 396ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),) 397$(obj)/core.o: scripts/target.json 398endif 399 400$(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*' 401$(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE 402 +$(call if_changed_rule,rustc_library) 403 404$(obj)/alloc.o: private skip_clippy = 1 405$(obj)/alloc.o: private skip_flags = -Wunreachable_pub 406$(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs) 407$(obj)/alloc.o: $(RUST_LIB_SRC)/alloc/src/lib.rs $(obj)/compiler_builtins.o FORCE 408 +$(call if_changed_rule,rustc_library) 409 410$(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE 411 +$(call if_changed_rule,rustc_library) 412 413$(obj)/bindings.o: $(src)/bindings/lib.rs \ 414 $(obj)/compiler_builtins.o \ 415 $(obj)/bindings/bindings_generated.rs \ 416 $(obj)/bindings/bindings_helpers_generated.rs FORCE 417 +$(call if_changed_rule,rustc_library) 418 419$(obj)/uapi.o: $(src)/uapi/lib.rs \ 420 $(obj)/compiler_builtins.o \ 421 $(obj)/uapi/uapi_generated.rs FORCE 422 +$(call if_changed_rule,rustc_library) 423 424$(obj)/kernel.o: private rustc_target_flags = --extern alloc \ 425 --extern build_error --extern macros --extern bindings --extern uapi 426$(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \ 427 $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE 428 +$(call if_changed_rule,rustc_library) 429 430endif # CONFIG_RUST 431
