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) $(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
101rustdoc-core: private rustc_target_flags = $(core-cfgs)
102rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
103	+$(call if_changed,rustdoc)
104
105rustdoc-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.
112rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \
113    -Arustdoc::broken_intra_doc_links
114rustdoc-alloc: $(RUST_LIB_SRC)/alloc/src/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
115	+$(call if_changed,rustdoc)
116
117rustdoc-kernel: private rustc_target_flags = --extern alloc \
118    --extern build_error --extern macros=$(objtree)/$(obj)/libmacros.so \
119    --extern bindings --extern uapi
120rustdoc-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
125quiet_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		-L$(objtree)/$(obj)/test \
133		--crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $<
134
135rusttestlib-build_error: $(src)/build_error.rs FORCE
136	+$(call if_changed,rustc_test_library)
137
138rusttestlib-macros: private rustc_target_flags = --extern proc_macro
139rusttestlib-macros: private rustc_test_library_proc = yes
140rusttestlib-macros: $(src)/macros/lib.rs FORCE
141	+$(call if_changed,rustc_test_library)
142
143rusttestlib-bindings: $(src)/bindings/lib.rs FORCE
144	+$(call if_changed,rustc_test_library)
145
146rusttestlib-uapi: $(src)/uapi/lib.rs FORCE
147	+$(call if_changed,rustc_test_library)
148
149quiet_cmd_rustdoc_test = RUSTDOC T $<
150      cmd_rustdoc_test = \
151	OBJTREE=$(abspath $(objtree)) \
152	$(RUSTDOC) --test $(rust_common_flags) \
153		@$(objtree)/include/generated/rustc_cfg \
154		$(rustc_target_flags) $(rustdoc_test_target_flags) \
155		$(rustdoc_test_quiet) \
156		-L$(objtree)/$(obj)/test --output $(rustdoc_output) \
157		--crate-name $(subst rusttest-,,$@) $<
158
159quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $<
160      cmd_rustdoc_test_kernel = \
161	rm -rf $(objtree)/$(obj)/test/doctests/kernel; \
162	mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \
163	OBJTREE=$(abspath $(objtree)) \
164	$(RUSTDOC) --test $(rust_flags) \
165		-L$(objtree)/$(obj) --extern alloc --extern kernel \
166		--extern build_error --extern macros \
167		--extern bindings --extern uapi \
168		--no-run --crate-name kernel -Zunstable-options \
169		--sysroot=/dev/null \
170		--test-builder $(objtree)/scripts/rustdoc_test_builder \
171		$< $(rustdoc_test_kernel_quiet); \
172	$(objtree)/scripts/rustdoc_test_gen
173
174%/doctests_kernel_generated.rs %/doctests_kernel_generated_kunit.c: \
175    $(src)/kernel/lib.rs $(obj)/kernel.o \
176    $(objtree)/scripts/rustdoc_test_builder \
177    $(objtree)/scripts/rustdoc_test_gen FORCE
178	+$(call if_changed,rustdoc_test_kernel)
179
180# We cannot use `-Zpanic-abort-tests` because some tests are dynamic,
181# so for the moment we skip `-Cpanic=abort`.
182quiet_cmd_rustc_test = RUSTC T  $<
183      cmd_rustc_test = \
184	OBJTREE=$(abspath $(objtree)) \
185	$(RUSTC) --test $(rust_common_flags) \
186		@$(objtree)/include/generated/rustc_cfg \
187		$(rustc_target_flags) --out-dir $(objtree)/$(obj)/test \
188		-L$(objtree)/$(obj)/test \
189		--crate-name $(subst rusttest-,,$@) $<; \
190	$(objtree)/$(obj)/test/$(subst rusttest-,,$@) $(rust_test_quiet) \
191		$(rustc_test_run_flags)
192
193rusttest: rusttest-macros rusttest-kernel
194
195rusttest-macros: private rustc_target_flags = --extern proc_macro
196rusttest-macros: private rustdoc_test_target_flags = --crate-type proc-macro
197rusttest-macros: $(src)/macros/lib.rs FORCE
198	+$(call if_changed,rustc_test)
199	+$(call if_changed,rustdoc_test)
200
201rusttest-kernel: private rustc_target_flags = --extern alloc \
202    --extern build_error --extern macros --extern bindings --extern uapi
203rusttest-kernel: $(src)/kernel/lib.rs \
204    rusttestlib-build_error rusttestlib-macros rusttestlib-bindings \
205    rusttestlib-uapi FORCE
206	+$(call if_changed,rustc_test)
207	+$(call if_changed,rustc_test_library)
208
209ifdef CONFIG_CC_IS_CLANG
210bindgen_c_flags = $(c_flags)
211else
212# bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC
213# plugin backend and/or the Clang driver would be perfectly compatible with GCC.
214#
215# For the moment, here we are tweaking the flags on the fly. This is a hack,
216# and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT`
217# if we end up using one of those structs).
218bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
219	-mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \
220	-mindirect-branch=thunk-extern -mindirect-branch-register \
221	-mfunction-return=thunk-extern -mrecord-mcount -mabi=lp64 \
222	-mindirect-branch-cs-prefix -mstack-protector-guard% -mtraceback=no \
223	-mno-pointers-to-nested-functions -mno-string \
224	-mno-strict-align -mstrict-align \
225	-fconserve-stack -falign-jumps=% -falign-loops=% \
226	-femit-struct-debug-baseonly -fno-ipa-cp-clone -fno-ipa-sra \
227	-fno-partial-inlining -fplugin-arg-arm_ssp_per_task_plugin-% \
228	-fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \
229	-fzero-call-used-regs=% -fno-stack-clash-protection \
230	-fno-inline-functions-called-once -fsanitize=bounds-strict \
231	-fstrict-flex-arrays=% -fmin-function-alignment=% \
232	--param=% --param asan-%
233
234# Derived from `scripts/Makefile.clang`.
235BINDGEN_TARGET_x86	:= x86_64-linux-gnu
236BINDGEN_TARGET_arm64	:= aarch64-linux-gnu
237BINDGEN_TARGET		:= $(BINDGEN_TARGET_$(SRCARCH))
238
239# All warnings are inhibited since GCC builds are very experimental,
240# many GCC warnings are not supported by Clang, they may only appear in
241# some configurations, with new GCC versions, etc.
242bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET)
243
244# Auto variable zero-initialization requires an additional special option with
245# clang that is going to be removed sometime in the future (likely in
246# clang-18), so make sure to pass this option only if clang supports it
247# (libclang major version < 16).
248#
249# https://github.com/llvm/llvm-project/issues/44842
250# https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags
251ifdef CONFIG_INIT_STACK_ALL_ZERO
252libclang_maj_ver=$(shell $(BINDGEN) $(srctree)/scripts/rust_is_available_bindgen_libclang.h 2>&1 | sed -ne 's/.*clang version \([0-9]*\).*/\1/p')
253ifeq ($(shell expr $(libclang_maj_ver) \< 16), 1)
254bindgen_extra_c_flags += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
255endif
256endif
257
258bindgen_c_flags = $(filter-out $(bindgen_skip_c_flags), $(c_flags)) \
259	$(bindgen_extra_c_flags)
260endif
261
262ifdef CONFIG_LTO
263bindgen_c_flags_lto = $(filter-out $(CC_FLAGS_LTO), $(bindgen_c_flags))
264else
265bindgen_c_flags_lto = $(bindgen_c_flags)
266endif
267
268bindgen_c_flags_final = $(bindgen_c_flags_lto) -D__BINDGEN__
269
270quiet_cmd_bindgen = BINDGEN $@
271      cmd_bindgen = \
272	$(BINDGEN) $< $(bindgen_target_flags) \
273		--use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \
274		--no-debug '.*' --enable-function-attribute-detection \
275		-o $@ -- $(bindgen_c_flags_final) -DMODULE \
276		$(bindgen_target_cflags) $(bindgen_target_extra)
277
278$(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \
279    $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters)
280$(obj)/bindings/bindings_generated.rs: private bindgen_target_extra = ; \
281    sed -Ei 's/pub const RUST_CONST_HELPER_([a-zA-Z0-9_]*)/pub const \1/g' $@
282$(obj)/bindings/bindings_generated.rs: $(src)/bindings/bindings_helper.h \
283    $(src)/bindgen_parameters FORCE
284	$(call if_changed_dep,bindgen)
285
286$(obj)/uapi/uapi_generated.rs: private bindgen_target_flags = \
287    $(shell grep -Ev '^#|^$$' $(src)/bindgen_parameters)
288$(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \
289    $(src)/bindgen_parameters FORCE
290	$(call if_changed_dep,bindgen)
291
292# See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn
293# with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here
294# given it is `libclang`; but for consistency, future Clang changes and/or
295# a potential future GCC backend for `bindgen`, we disable it too.
296$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \
297    --blocklist-type '.*' --allowlist-var '' \
298    --allowlist-function 'rust_helper_.*'
299$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \
300    -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations
301$(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \
302    sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n    pub fn \1/g' $@
303$(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers/helpers.c FORCE
304	$(call if_changed_dep,bindgen)
305
306quiet_cmd_exports = EXPORTS $@
307      cmd_exports = \
308	$(NM) -p --defined-only $< \
309		| awk '$$2~/(T|R|D|B)/ && $$3!~/__cfi/ {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$3}' > $@
310
311$(obj)/exports_core_generated.h: $(obj)/core.o FORCE
312	$(call if_changed,exports)
313
314$(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE
315	$(call if_changed,exports)
316
317# Even though Rust kernel modules should never use the bindings directly,
318# symbols from the `bindings` crate and the C helpers need to be exported
319# because Rust generics and inlined functions may not get their code generated
320# in the crate where they are defined. Other helpers, called from non-inline
321# functions, may not be exported, in principle. However, in general, the Rust
322# compiler does not guarantee codegen will be performed for a non-inline
323# function either. Therefore, we export all symbols from helpers and bindings.
324# In the future, this may be revisited to reduce the number of exports after
325# the compiler is informed about the places codegen is required.
326$(obj)/exports_helpers_generated.h: $(obj)/helpers/helpers.o FORCE
327	$(call if_changed,exports)
328
329$(obj)/exports_bindings_generated.h: $(obj)/bindings.o FORCE
330	$(call if_changed,exports)
331
332$(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE
333	$(call if_changed,exports)
334
335quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
336      cmd_rustc_procmacro = \
337	$(RUSTC_OR_CLIPPY) $(rust_common_flags) \
338		-Clinker-flavor=gcc -Clinker=$(HOSTCC) \
339		-Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
340		--emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \
341		--crate-type proc-macro \
342		--crate-name $(patsubst lib%.so,%,$(notdir $@)) $<
343
344# Procedural macros can only be used with the `rustc` that compiled it.
345$(obj)/libmacros.so: $(src)/macros/lib.rs FORCE
346	+$(call if_changed_dep,rustc_procmacro)
347
348quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@
349      cmd_rustc_library = \
350	OBJTREE=$(abspath $(objtree)) \
351	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
352		$(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \
353		--emit=dep-info=$(depfile) --emit=obj=$@ \
354		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
355		--crate-type rlib -L$(objtree)/$(obj) \
356		--crate-name $(patsubst %.o,%,$(notdir $@)) $< \
357		--sysroot=/dev/null \
358	$(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@) \
359	$(cmd_objtool)
360
361rust-analyzer:
362	$(Q)$(srctree)/scripts/generate_rust_analyzer.py \
363		--cfgs='core=$(core-cfgs)' --cfgs='alloc=$(alloc-cfgs)' \
364		$(realpath $(srctree)) $(realpath $(objtree)) \
365		$(rustc_sysroot) $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \
366		$(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json
367
368redirect-intrinsics = \
369	__addsf3 __eqsf2 __extendsfdf2 __gesf2 __lesf2 __ltsf2 __mulsf3 __nesf2 __truncdfsf2 __unordsf2 \
370	__adddf3 __eqdf2 __ledf2 __ltdf2 __muldf3 __unorddf2 \
371	__muloti4 __multi3 \
372	__udivmodti4 __udivti3 __umodti3
373
374ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),)
375	# These intrinsics are defined for ARM64 and RISCV64
376	redirect-intrinsics += \
377		__ashrti3 \
378		__ashlti3 __lshrti3
379endif
380
381define rule_rustc_library
382	$(call cmd_and_fixdep,rustc_library)
383	$(call cmd,gen_objtooldep)
384endef
385
386$(obj)/core.o: private skip_clippy = 1
387$(obj)/core.o: private skip_flags = -Wunreachable_pub
388$(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
389$(obj)/core.o: private rustc_target_flags = $(core-cfgs)
390$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \
391    $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE
392	+$(call if_changed_rule,rustc_library)
393ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),)
394$(obj)/core.o: scripts/target.json
395endif
396
397$(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*'
398$(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
399	+$(call if_changed_rule,rustc_library)
400
401$(obj)/alloc.o: private skip_clippy = 1
402$(obj)/alloc.o: private skip_flags = -Wunreachable_pub
403$(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs)
404$(obj)/alloc.o: $(RUST_LIB_SRC)/alloc/src/lib.rs $(obj)/compiler_builtins.o FORCE
405	+$(call if_changed_rule,rustc_library)
406
407$(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE
408	+$(call if_changed_rule,rustc_library)
409
410$(obj)/bindings.o: $(src)/bindings/lib.rs \
411    $(obj)/compiler_builtins.o \
412    $(obj)/bindings/bindings_generated.rs \
413    $(obj)/bindings/bindings_helpers_generated.rs FORCE
414	+$(call if_changed_rule,rustc_library)
415
416$(obj)/uapi.o: $(src)/uapi/lib.rs \
417    $(obj)/compiler_builtins.o \
418    $(obj)/uapi/uapi_generated.rs FORCE
419	+$(call if_changed_rule,rustc_library)
420
421$(obj)/kernel.o: private rustc_target_flags = --extern alloc \
422    --extern build_error --extern macros --extern bindings --extern uapi
423$(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
424    $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE
425	+$(call if_changed_rule,rustc_library)
426
427endif # CONFIG_RUST
428