Merge pull request #627 from ojeda/rust-test-ci

Build system review

Author: ojeda

Makefile

@@ -1162,11 +1162,7 @@ export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
 ifeq ($(KBUILD_EXTMOD),)
 core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
 core-$(CONFIG_BLOCK)	+= block/
-
-# Keep this one as an `ifdef` block since its `Makefile` runs `rustc`.
-ifdef CONFIG_RUST
-core-y			+= rust/
-endif
+core-$(CONFIG_RUST)	+= rust/
 
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
@@ -1269,6 +1265,7 @@ prepare0: archprepare
 	$(Q)$(MAKE) $(build)=scripts/mod
 	$(Q)$(MAKE) $(build)=.
 ifdef CONFIG_RUST
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v
 	$(Q)$(MAKE) $(build)=rust
 endif
 
@@ -1583,7 +1580,7 @@ MRPROPER_FILES += include/config include/generated          \
 		  certs/x509.genkey \
 		  vmlinux-gdb.py \
 		  *.spec \
-		  rust/*_generated.h rust/*_generated.rs rust/libmacros.so
+		  rust/libmacros.so
 
 # clean - Delete most, but leave enough to build external modules
 #
@@ -1608,6 +1605,9 @@ $(mrproper-dirs):
 
 mrproper: clean $(mrproper-dirs)
 	$(call cmd,rmfiles)
+	@find . $(RCS_FIND_IGNORE) \
+		\( -name '*.rmeta' \) \
+		-type f -print | xargs rm -f
 
 # distclean
 #
@@ -1786,7 +1786,7 @@ $(DOC_TARGETS):
 # "Is Rust available?" target
 PHONY += rustavailable
 rustavailable:
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v && echo >&2 "Rust is available!"
 
 # Documentation target
 #
@@ -1992,7 +1992,6 @@ clean: $(clean-dirs)
 	$(call cmd,rmfiles)
 	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
 		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
-		-o -name '*.rmeta' \
 		-o -name '*.ko.*' \
 		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
 		-o -name '*.dwo' -o -name '*.lst' \

init/Kconfig

@@ -2060,7 +2060,6 @@ config RUST
 	bool "Rust support"
 	depends on RUST_IS_AVAILABLE
 	depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64 || RISCV
-	depends on !COMPILE_TEST
 	depends on !MODVERSIONS
 	depends on !GCC_PLUGIN_RANDSTRUCT
 	default n
@@ -2078,14 +2077,14 @@ config RUST
 	  If unsure, say N.
 
 config RUSTC_VERSION_TEXT
-	depends on RUST
 	string
-	default $(shell,$(RUSTC) --version)
+	depends on RUST
+	default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
 
 config BINDGEN_VERSION_TEXT
-	depends on RUST
 	string
-	default $(shell,$(BINDGEN) --version)
+	depends on RUST
+	default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n)
 
 #
 # Place an empty function call at each tracepoint site. Can be

rust/Makefile

@@ -1,22 +1,26 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_RUST) += core.o compiler_builtins.o helpers.o
-extra-$(CONFIG_RUST) += exports_core_generated.h
+always-$(CONFIG_RUST) += exports_core_generated.h
 
-extra-$(CONFIG_RUST) += libmacros.so
+always-$(CONFIG_RUST) += libmacros.so
+no-clean-files += libmacros.so
 
-extra-$(CONFIG_RUST) += bindings_generated.rs bindings_helpers_generated.rs
+always-$(CONFIG_RUST) += bindings_generated.rs bindings_helpers_generated.rs
 obj-$(CONFIG_RUST) += alloc.o kernel.o
-extra-$(CONFIG_RUST) += exports_alloc_generated.h exports_kernel_generated.h
+always-$(CONFIG_RUST) += exports_alloc_generated.h exports_kernel_generated.h
 
 ifdef CONFIG_RUST_BUILD_ASSERT_DENY
-extra-$(CONFIG_RUST) += build_error.o
+always-$(CONFIG_RUST) += build_error.o
 else
 obj-$(CONFIG_RUST) += build_error.o
 endif
 
 obj-$(CONFIG_RUST) += exports.o
 
+# Avoids running `$(RUSTC)` for the sysroot when it may not be available.
+ifdef CONFIG_RUST
+
 ifeq ($(quiet),silent_)
 cargo_quiet=-q
 rust_test_quiet=-q
@@ -302,8 +306,8 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
 	$(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
 
 # `$(rust_flags)` is passed in case the user added `--sysroot`.
-rustc_sysroot = $(shell $(RUSTC) $(rust_flags) --print sysroot)
-rustc_host_target = $(shell $(RUSTC) --version --verbose | grep -F 'host: ' | cut -d' ' -f2)
+rustc_sysroot := $(shell $(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
 
 rust-analyzer:
@@ -335,14 +339,14 @@ $(objtree)/rust/kernel.o: $(srctree)/rust/kernel/lib.rs $(objtree)/rust/alloc.o
     $(objtree)/rust/bindings_helpers_generated.rs FORCE
 	$(call if_changed_dep,rustc_library)
 
-# Targets that need to expand twice
-.SECONDEXPANSION:
 $(objtree)/rust/core.o: private skip_clippy = 1
 $(objtree)/rust/core.o: private skip_flags = -Dunreachable_pub --edition=2021
 $(objtree)/rust/core.o: private rustc_target_flags = $(core-cfgs) --edition=2018
-$(objtree)/rust/core.o: $$(RUST_LIB_SRC)/core/src/lib.rs FORCE
+$(objtree)/rust/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 	$(call if_changed_dep,rustc_library)
 
 rustdoc-core: private rustc_target_flags = $(core-cfgs)
-rustdoc-core: $$(RUST_LIB_SRC)/core/src/lib.rs FORCE
+rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 	$(call if_changed,rustdoc)
+
+endif # CONFIG_RUST

scripts/rust-is-available.sh

@@ -44,7 +44,11 @@ fi
 # Check that the Rust compiler version is suitable.
 #
 # Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
-rust_compiler_version=$("$RUSTC" --version | cut -f2 -d' ' | cut -f1 -d'-')
+rust_compiler_version=$( \
+	LC_ALL=C "$RUSTC" --version 2>/dev/null \
+		| head -n 1 \
+		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+)
 rust_compiler_min_version=$($min_tool_version rustc)
 rust_compiler_cversion=$(get_canonical_version $rust_compiler_version)
 rust_compiler_min_cversion=$(get_canonical_version $rust_compiler_min_version)
@@ -69,7 +73,11 @@ fi
 # Check that the Rust bindings generator is suitable.
 #
 # Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
-rust_bindings_generator_version=$("$BINDGEN" --version | cut -f2 -d' ' | cut -f1 -d'-')
+rust_bindings_generator_version=$( \
+	LC_ALL=C "$BINDGEN" --version 2>/dev/null \
+		| head -n 1 \
+		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+)
 rust_bindings_generator_min_version=$($min_tool_version bindgen)
 rust_bindings_generator_cversion=$(get_canonical_version $rust_bindings_generator_version)
 rust_bindings_generator_min_cversion=$(get_canonical_version $rust_bindings_generator_min_version)
@@ -92,15 +100,11 @@ if [ "$1" = -v ] && [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_ge
 fi
 
 # Check that the `libclang` used by the Rust bindings generator is suitable.
-#
-# There may be a better way to do this in the future,
-# see https://github.com/rust-lang/rust-bindgen/issues/2138
-bindgen_libclang_full_version=$(\
-	"$BINDGEN" $(dirname $0)/rust-is-available-bindgen-libclang.h 2>&1 >/dev/null \
-		| grep -F 'clang version' \
-		| sed -E 's:^.*(clang version .*) \[.*$:\1:' \
+bindgen_libclang_version=$( \
+	LC_ALL=C "$BINDGEN" $(dirname $0)/rust-is-available-bindgen-libclang.h 2>&1 >/dev/null \
+		| grep -F 'clang version ' \
+		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
 )
-bindgen_libclang_version=$(echo "$bindgen_libclang_full_version" | cut -f3 -d' ')
 bindgen_libclang_min_version=$($min_tool_version llvm)
 bindgen_libclang_cversion=$(get_canonical_version $bindgen_libclang_version)
 bindgen_libclang_min_cversion=$(get_canonical_version $bindgen_libclang_min_version)
@@ -115,17 +119,24 @@ if [ "$bindgen_libclang_cversion" -lt "$bindgen_libclang_min_cversion" ]; then
 	exit 1
 fi
 
-# If the C compiler is Clang, then we can also check whether its full version
-# matches exactly the `libclang` used by the Rust bindings generator.
+# If the C compiler is Clang, then we can also check whether its version
+# matches the `libclang` version used by the Rust bindings generator.
+#
+# In the future, we might be able to perform a full version check, see
+# https://github.com/rust-lang/rust-bindgen/issues/2138.
 if [ "$1" = -v ]; then
 	cc_name=$($(dirname $0)/cc-version.sh "$CC" | cut -f1 -d' ')
 	if [ "$cc_name" = Clang ]; then
-		clang_full_version=$("$CC" --version | grep -F 'clang version')
-		if [ "$clang_full_version" != "$bindgen_libclang_full_version" ]; then
+		clang_version=$( \
+			LC_ALL=C "$CC" --version 2>/dev/null \
+				| head -n 1 \
+				| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+		)
+		if [ "$clang_version" != "$bindgen_libclang_version" ]; then
 			echo >&2 "***"
-			echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN') full version does not match Clang's. This may be a problem."
-			echo >&2 "***   libclang: $bindgen_libclang_full_version"
-			echo >&2 "***   Clang:    $clang_full_version"
+			echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN') version does not match Clang's. This may be a problem."
+			echo >&2 "***   libclang version: $bindgen_libclang_version"
+			echo >&2 "***   Clang version:    $clang_version"
 			echo >&2 "***"
 		fi
 	fi
@@ -146,8 +157,3 @@ if [ ! -e "$rustc_src_core" ]; then
 	fi
 	exit 1
 fi
-
-# Success!
-if [ "$1" = -v ]; then
-	echo >&2 "Rust is available!"
-fi