rust/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2
   3 obj-$(CONFIG_RUST) += core.o compiler_builtins.o
   4 always-$(CONFIG_RUST) += exports_core_generated.h
   5
   6 # Missing prototypes are expected in the helpers since these are exported
   7 # for Rust only, thus there is no header nor prototypes.
   8 obj-$(CONFIG_RUST) += helpers.o
   9 CFLAGS_REMOVE_helpers.o = -Wmissing-prototypes -Wmissing-declarations
  10
  11 always-$(CONFIG_RUST) += libmacros.so
  12 no-clean-files += libmacros.so
  13
  14 always-$(CONFIG_RUST) += bindings/bindings_generated.rs bindings/bindings_helpers_generated.rs
  15 obj-$(CONFIG_RUST) += alloc.o bindings.o kernel.o
  16 always-$(CONFIG_RUST) += exports_alloc_generated.h exports_bindings_generated.h \
  17     exports_kernel_generated.h
  18
  19 always-$(CONFIG_RUST) += uapi/uapi_generated.rs
  20 obj-$(CONFIG_RUST) += uapi.o
  21
  22 ifdef CONFIG_RUST_BUILD_ASSERT_ALLOW
  23 obj-$(CONFIG_RUST) += build_error.o
  24 else
  25 always-$(CONFIG_RUST) += build_error.o
  26 endif
  27
  28 obj-$(CONFIG_RUST) += exports.o
  29
  30 # Avoids running `$(RUSTC)` for the sysroot when it may not be available.
  31 ifdef CONFIG_RUST
  32
  33 # `$(rust_flags)` is passed in case the user added `--sysroot`.
  34 rustc_sysroot := $(shell $(RUSTC) $(rust_flags) --print sysroot)
  35 rustc_host_target := $(shell $(RUSTC) --version --verbose | grep -F 'host: ' | cut -d' ' -f2)
  36 RUST_LIB_SRC ?= $(rustc_sysroot)/lib/rustlib/src/rust/library
  37
  38 ifeq ($(quiet),silent_)
  39 cargo_quiet=-q
  40 rust_test_quiet=-q
  41 rustdoc_test_quiet=--test-args -q
  42 else ifeq ($(quiet),quiet_)
  43 rust_test_quiet=-q
  44 rustdoc_test_quiet=--test-args -q
  45 else
  46 cargo_quiet=--verbose
  47 endif
  48
  49 core-cfgs = \
  50     --cfg no_fp_fmt_parse
  51
  52 alloc-cfgs = \
  53     --cfg no_borrow \
  54     --cfg no_fmt \
  55     --cfg no_global_oom_handling \
  56     --cfg no_macros \
  57     --cfg no_rc \
  58     --cfg no_str \
  59     --cfg no_string \
  60     --cfg no_sync \
  61     --cfg no_thin
  62
  63 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
  64       cmd_rustdoc = \
  65         OBJTREE=$(abspath $(objtree)) \
  66         $(RUSTDOC) $(if $(rustdoc_host),$(rust_common_flags),$(rust_flags)) \
  67                 $(rustc_target_flags) -L$(objtree)/$(obj) \
  68                 --output $(objtree)/$(obj)/doc \
  69                 --crate-name $(subst rustdoc-,,$@) \
  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.
  83 rustdoc: rustdoc-core rustdoc-macros rustdoc-compiler_builtins \
  84     rustdoc-alloc rustdoc-kernel
  85         $(Q)cp $(srctree)/Documentation/images/logo.svg $(objtree)/$(obj)/doc
  86         $(Q)cp $(srctree)/Documentation/images/COPYING-logo $(objtree)/$(obj)/doc
  87         $(Q)find $(objtree)/$(obj)/doc -name '*.html' -type f -print0 | xargs -0 sed -Ei \
  88                 -e 's:rust-logo\.svg:logo.svg:g' \
  89                 -e 's:rust-logo\.png:logo.svg:g' \
  90                 -e 's:favicon\.svg:logo.svg:g' \
  91                 -e 's:<link rel="alternate icon" type="image/png" href="[./]*favicon-(16x16|32x32)\.png">::g'
  92         $(Q)echo '.logo-container > img { object-fit: contain; }' \
  93                 >> $(objtree)/$(obj)/doc/rustdoc.css
  94
  95 rustdoc-macros: private rustdoc_host = yes
  96 rustdoc-macros: private rustc_target_flags = --crate-type proc-macro \
  97     --extern proc_macro
  98 rustdoc-macros: $(src)/macros/lib.rs FORCE
  99         $(call if_changed,rustdoc)
 100
 101 rustdoc-core: private rustc_target_flags = $(core-cfgs)
 102 rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 103         $(call if_changed,rustdoc)
 104
 105 rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE
 106         $(call if_changed,rustdoc)
 107
 108 # We need to allow `rustdoc::broken_intra_doc_links` because some
 109 # `no_global_oom_handling` functions refer to non-`no_global_oom_handling`
 110 # functions. Ideally `rustdoc` would have a way to distinguish broken links
 111 # due to things that are "configured out" vs. entirely non-existing ones.
 112 rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \
 113     -Arustdoc::broken_intra_doc_links
 114 rustdoc-alloc: $(src)/alloc/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
 115         $(call if_changed,rustdoc)
 116
 117 rustdoc-kernel: private rustc_target_flags = --extern alloc \
 118     --extern build_error --extern macros=$(objtree)/$(obj)/libmacros.so \
 119     --extern bindings --extern uapi
 120 rustdoc-kernel: $(src)/kernel/lib.rs rustdoc-core rustdoc-macros \
 121     rustdoc-compiler_builtins rustdoc-alloc $(obj)/libmacros.so \
 122     $(obj)/bindings.o FORCE
 123         $(call if_changed,rustdoc)
 124
 125 quiet_cmd_rustc_test_library = RUSTC TL $<
 126       cmd_rustc_test_library = \
 127         OBJTREE=$(abspath $(objtree)) \
 128         $(RUSTC) $(rust_common_flags) \
 129                 @$(objtree)/include/generated/rustc_cfg $(rustc_target_flags) \
 130                 --crate-type $(if $(rustc_test_library_proc),proc-macro,rlib) \
 131                 --out-dir $(objtree)/$(obj)/test --cfg testlib \
 132                 --sysroot $(objtree)/$(obj)/test/sysroot \
 133                 -L$(objtree)/$(obj)/test \
 134                 --crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $<
 135
 136 rusttestlib-build_error: $(src)/build_error.rs rusttest-prepare FORCE
 137         $(call if_changed,rustc_test_library)
 138
 139 rusttestlib-macros: private rustc_target_flags = --extern proc_macro
 140 rusttestlib-macros: private rustc_test_library_proc = yes
 141 rusttestlib-macros: $(src)/macros/lib.rs rusttest-prepare FORCE
 142         $(call if_changed,rustc_test_library)
 143
 144 rusttestlib-bindings: $(src)/bindings/lib.rs rusttest-prepare FORCE
 145         $(call if_changed,rustc_test_library)
 146
 147 rusttestlib-uapi: $(src)/uapi/lib.rs rusttest-prepare FORCE
 148         $(call if_changed,rustc_test_library)
 149
 150 quiet_cmd_rustdoc_test = RUSTDOC T $<
 151       cmd_rustdoc_test = \
 152         OBJTREE=$(abspath $(objtree)) \
 153         $(RUSTDOC) --test $(rust_common_flags) \
 154                 @$(objtree)/include/generated/rustc_cfg \
 155                 $(rustc_target_flags) $(rustdoc_test_target_flags) \
 156                 --sysroot $(objtree)/$(obj)/test/sysroot $(rustdoc_test_quiet) \
 157                 -L$(objtree)/$(obj)/test --output $(objtree)/$(obj)/doc \
 158                 --crate-name $(subst rusttest-,,$@) $<
 159
 160 # We cannot use `-Zpanic-abort-tests` because some tests are dynamic,
 161 # so for the moment we skip `-Cpanic=abort`.
 162 quiet_cmd_rustc_test = RUSTC T  $<
 163       cmd_rustc_test = \
 164         OBJTREE=$(abspath $(objtree)) \
 165         $(RUSTC) --test $(rust_common_flags) \
 166                 @$(objtree)/include/generated/rustc_cfg \
 167                 $(rustc_target_flags) --out-dir $(objtree)/$(obj)/test \
 168                 --sysroot $(objtree)/$(obj)/test/sysroot \
 169                 -L$(objtree)/$(obj)/test \
 170                 --crate-name $(subst rusttest-,,$@) $<; \
 171         $(objtree)/$(obj)/test/$(subst rusttest-,,$@) $(rust_test_quiet) \
 172                 $(rustc_test_run_flags)
 173
 174 rusttest: rusttest-macros rusttest-kernel
 175
 176 # This prepares a custom sysroot with our custom `alloc` instead of
 177 # the standard one.
 178 #
 179 # This requires several hacks:
 180 #   - Unlike `core` and `alloc`, `std` depends on more than a dozen crates,
 181 #     including third-party crates that need to be downloaded, plus custom
 182 #     `build.rs` steps. Thus hardcoding things here is not maintainable.
 183 #   - `cargo` knows how to build the standard library, but it is an unstable
 184 #     feature so far (`-Zbuild-std`).
 185 #   - `cargo` only considers the use case of building the standard library
 186 #     to use it in a given package. Thus we need to create a dummy package
 187 #     and pick the generated libraries from there.
 188 #   - Since we only keep a subset of upstream `alloc` in-tree, we need
 189 #     to recreate it on the fly by putting our sources on top.
 190 #   - The usual ways of modifying the dependency graph in `cargo` do not seem
 191 #     to apply for the `-Zbuild-std` steps, thus we have to mislead it
 192 #     by modifying the sources in the sysroot.
 193 #   - To avoid messing with the user's Rust installation, we create a clone
 194 #     of the sysroot. However, `cargo` ignores `RUSTFLAGS` in the `-Zbuild-std`
 195 #     steps, thus we use a wrapper binary passed via `RUSTC` to pass the flag.
 196 #
 197 # In the future, we hope to avoid the whole ordeal by either:
 198 #   - Making the `test` crate not depend on `std` (either improving upstream
 199 #     or having our own custom crate).
 200 #   - Making the tests run in kernel space (requires the previous point).
 201 #   - Making `std` and friends be more like a "normal" crate, so that
 202 #     `-Zbuild-std` and related hacks are not needed.
 203 quiet_cmd_rustsysroot = RUSTSYSROOT
 204       cmd_rustsysroot = \
 205         rm -rf $(objtree)/$(obj)/test; \
 206         mkdir -p $(objtree)/$(obj)/test; \
 207         cp -a $(rustc_sysroot) $(objtree)/$(obj)/test/sysroot; \
 208         cp -r $(srctree)/$(src)/alloc/* \
 209                 $(objtree)/$(obj)/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \
 210         echo '\#!/bin/sh' > $(objtree)/$(obj)/test/rustc_sysroot; \
 211         echo "$(RUSTC) --sysroot=$(abspath $(objtree)/$(obj)/test/sysroot) \"\$$@\"" \
 212                 >> $(objtree)/$(obj)/test/rustc_sysroot; \
 213         chmod u+x $(objtree)/$(obj)/test/rustc_sysroot; \
 214         $(CARGO) -q new $(objtree)/$(obj)/test/dummy; \
 215         RUSTC=$(objtree)/$(obj)/test/rustc_sysroot $(CARGO) $(cargo_quiet) \
 216                 test -Zbuild-std --target $(rustc_host_target) \
 217                 --manifest-path $(objtree)/$(obj)/test/dummy/Cargo.toml; \
 218         rm $(objtree)/$(obj)/test/sysroot/lib/rustlib/$(rustc_host_target)/lib/*; \
 219         cp $(objtree)/$(obj)/test/dummy/target/$(rustc_host_target)/debug/deps/* \
 220                 $(objtree)/$(obj)/test/sysroot/lib/rustlib/$(rustc_host_target)/lib
 221
 222 rusttest-prepare: FORCE
 223         $(call if_changed,rustsysroot)
 224
 225 rusttest-macros: private rustc_target_flags = --extern proc_macro
 226 rusttest-macros: private rustdoc_test_target_flags = --crate-type proc-macro
 227 rusttest-macros: $(src)/macros/lib.rs rusttest-prepare FORCE
 228         $(call if_changed,rustc_test)
 229         $(call if_changed,rustdoc_test)
 230
 231 rusttest-kernel: private rustc_target_flags = --extern alloc \
 232     --extern build_error --extern macros --extern bindings --extern uapi
 233 rusttest-kernel: $(src)/kernel/lib.rs rusttest-prepare \
 234     rusttestlib-build_error rusttestlib-macros rusttestlib-bindings \
 235     rusttestlib-uapi FORCE
 236         $(call if_changed,rustc_test)
 237         $(call if_changed,rustc_test_library)
 238
 239 ifdef CONFIG_CC_IS_CLANG
 240 bindgen_c_flags = $(c_flags)
 241 else
 242 # bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC
 243 # plugin backend and/or the Clang driver would be perfectly compatible with GCC.
 244 #
 245 # For the moment, here we are tweaking the flags on the fly. This is a hack,
 246 # and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT`
 247 # if we end up using one of those structs).
 248 bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
 249         -mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \
 250         -mindirect-branch=thunk-extern -mindirect-branch-register \
 251         -mfunction-return=thunk-extern -mrecord-mcount -mabi=lp64 \
 252         -mindirect-branch-cs-prefix -mstack-protector-guard% -mtraceback=no \
 253         -mno-pointers-to-nested-functions -mno-string \
 254         -mno-strict-align -mstrict-align \
 255         -fconserve-stack -falign-jumps=% -falign-loops=% \
 256         -femit-struct-debug-baseonly -fno-ipa-cp-clone -fno-ipa-sra \
 257         -fno-partial-inlining -fplugin-arg-arm_ssp_per_task_plugin-% \
 258         -fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \
 259         -fzero-call-used-regs=% -fno-stack-clash-protection \
 260         -fno-inline-functions-called-once \
 261         --param=% --param asan-%
 262
 263 # Derived from `scripts/Makefile.clang`.
 264 BINDGEN_TARGET_x86      := x86_64-linux-gnu
 265 BINDGEN_TARGET          := $(BINDGEN_TARGET_$(SRCARCH))
 266
 267 # All warnings are inhibited since GCC builds are very experimental,
 268 # many GCC warnings are not supported by Clang, they may only appear in
 269 # some configurations, with new GCC versions, etc.
 270 bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET)
 271
 272 # Auto variable zero-initialization requires an additional special option with
 273 # clang that is going to be removed sometime in the future (likely in
 274 # clang-18), so make sure to pass this option only if clang supports it
 275 # (libclang major version < 16).
 276 #
 277 # https://github.com/llvm/llvm-project/issues/44842
 278 # https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags
 279 ifdef CONFIG_INIT_STACK_ALL_ZERO
 280 libclang_maj_ver=$(shell $(BINDGEN) $(srctree)/scripts/rust_is_available_bindgen_libclang.h 2>&1 | sed -ne 's/.*clang version \([0-9]*\).*/\1/p')
 281 ifeq ($(shell expr $(libclang_maj_ver) \< 16), 1)
 282 bindgen_extra_c_flags += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 283 endif
 284 endif
 285
 286 bindgen_c_flags = $(filter-out $(bindgen_skip_c_flags), $(c_flags)) \
 287         $(bindgen_extra_c_flags)
 288 endif
 289
 290 ifdef CONFIG_LTO
 291 bindgen_c_flags_lto = $(filter-out $(CC_FLAGS_LTO), $(bindgen_c_flags))
 292 else
 293 bindgen_c_flags_lto = $(bindgen_c_flags)
 294 endif
 295
 296 bindgen_c_flags_final = $(bindgen_c_flags_lto) -D__BINDGEN__
 297
 298 quiet_cmd_bindgen = BINDGEN $@
 299       cmd_bindgen = \
 300         $(BINDGEN) $< $(bindgen_target_flags) \
 301                 --use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \
 302                 --no-debug '.*' \
 303                 --size_t-is-usize -o $@ -- $(bindgen_c_flags_final) -DMODULE \
 304                 $(bindgen_target_cflags) $(bindgen_target_extra)
 305
 306 $(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \
 307     $(shell grep -v '^#\|^$$' $(srctree)/$(src)/bindgen_parameters)
 308 $(obj)/bindings/bindings_generated.rs: $(src)/bindings/bindings_helper.h \
 309     $(src)/bindgen_parameters FORCE
 310         $(call if_changed_dep,bindgen)
 311
 312 $(obj)/uapi/uapi_generated.rs: private bindgen_target_flags = \
 313     $(shell grep -v '^#\|^$$' $(srctree)/$(src)/bindgen_parameters)
 314 $(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \
 315     $(src)/bindgen_parameters FORCE
 316         $(call if_changed_dep,bindgen)
 317
 318 # See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn
 319 # with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here
 320 # given it is `libclang`; but for consistency, future Clang changes and/or
 321 # a potential future GCC backend for `bindgen`, we disable it too.
 322 $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \
 323     --blacklist-type '.*' --whitelist-var '' \
 324     --whitelist-function 'rust_helper_.*'
 325 $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \
 326     -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations
 327 $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \
 328     sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n    pub fn \1/g' $@
 329 $(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers.c FORCE
 330         $(call if_changed_dep,bindgen)
 331
 332 quiet_cmd_exports = EXPORTS $@
 333       cmd_exports = \
 334         $(NM) -p --defined-only $< \
 335                 | grep -E ' (T|R|D) ' | cut -d ' ' -f 3 \
 336                 | xargs -Isymbol \
 337                 echo 'EXPORT_SYMBOL_RUST_GPL(symbol);' > $@
 338
 339 $(obj)/exports_core_generated.h: $(obj)/core.o FORCE
 340         $(call if_changed,exports)
 341
 342 $(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE
 343         $(call if_changed,exports)
 344
 345 $(obj)/exports_bindings_generated.h: $(obj)/bindings.o FORCE
 346         $(call if_changed,exports)
 347
 348 $(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE
 349         $(call if_changed,exports)
 350
 351 quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
 352       cmd_rustc_procmacro = \
 353         $(RUSTC_OR_CLIPPY) $(rust_common_flags) \
 354                 --emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \
 355                 --crate-type proc-macro \
 356                 --crate-name $(patsubst lib%.so,%,$(notdir $@)) $<
 357
 358 # Procedural macros can only be used with the `rustc` that compiled it.
 359 # Therefore, to get `libmacros.so` automatically recompiled when the compiler
 360 # version changes, we add `core.o` as a dependency (even if it is not needed).
 361 $(obj)/libmacros.so: $(src)/macros/lib.rs $(obj)/core.o FORCE
 362         $(call if_changed_dep,rustc_procmacro)
 363
 364 quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@
 365       cmd_rustc_library = \
 366         OBJTREE=$(abspath $(objtree)) \
 367         $(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
 368                 $(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \
 369                 --emit=dep-info=$(depfile) --emit=obj=$@ \
 370                 --emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
 371                 --crate-type rlib -L$(objtree)/$(obj) \
 372                 --crate-name $(patsubst %.o,%,$(notdir $@)) $< \
 373         $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
 374
 375 rust-analyzer:
 376         $(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) \
 377                 $(RUST_LIB_SRC) > $(objtree)/rust-project.json
 378
 379 redirect-intrinsics = \
 380         __eqsf2 __gesf2 __lesf2 __nesf2 __unordsf2 \
 381         __unorddf2 \
 382         __muloti4 __multi3 \
 383         __udivmodti4 __udivti3 __umodti3
 384
 385 ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),)
 386         # These intrinsics are defined for ARM64 and RISCV64
 387         redirect-intrinsics += \
 388                 __ashrti3 \
 389                 __ashlti3 __lshrti3
 390 endif
 391
 392 $(obj)/core.o: private skip_clippy = 1
 393 $(obj)/core.o: private skip_flags = -Dunreachable_pub
 394 $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
 395 $(obj)/core.o: private rustc_target_flags = $(core-cfgs)
 396 $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs scripts/target.json FORCE
 397         $(call if_changed_dep,rustc_library)
 398
 399 $(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*'
 400 $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
 401         $(call if_changed_dep,rustc_library)
 402
 403 $(obj)/alloc.o: private skip_clippy = 1
 404 $(obj)/alloc.o: private skip_flags = -Dunreachable_pub
 405 $(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs)
 406 $(obj)/alloc.o: $(src)/alloc/lib.rs $(obj)/compiler_builtins.o FORCE
 407         $(call if_changed_dep,rustc_library)
 408
 409 $(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE
 410         $(call if_changed_dep,rustc_library)
 411
 412 $(obj)/bindings.o: $(src)/bindings/lib.rs \
 413     $(obj)/compiler_builtins.o \
 414     $(obj)/bindings/bindings_generated.rs \
 415     $(obj)/bindings/bindings_helpers_generated.rs FORCE
 416         $(call if_changed_dep,rustc_library)
 417
 418 $(obj)/uapi.o: $(src)/uapi/lib.rs \
 419     $(obj)/compiler_builtins.o \
 420     $(obj)/uapi/uapi_generated.rs FORCE
 421         $(call if_changed_dep,rustc_library)
 422
 423 $(obj)/kernel.o: private rustc_target_flags = --extern alloc \
 424     --extern build_error --extern macros --extern bindings --extern uapi
 425 $(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
 426     $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE
 427         $(call if_changed_dep,rustc_library)
 428
 429 endif # CONFIG_RUST