package/pkg-cargo.mk - buildroot - Git at Google

 ################################################################################
 # Cargo package infrastructure
 #
 # This file implements an infrastructure that eases development of package
 # .mk files for Cargo packages. It should be used for all packages that use
 # Cargo as their build system.
 #
 # See the Buildroot documentation for details on the usage of this
 # infrastructure
 #
 # In terms of implementation, this Cargo infrastructure requires the .mk file
 # to only specify metadata information about the package: name, version,
 # download URL, etc.
 #
 # We still allow the package .mk file to override what the different steps
 # are doing, if needed. For example, if <PKG>_BUILD_CMDS is already defined,
 # it is used as the list of commands to perform to build the package,
 # instead of the default Cargo behaviour. The package can also define some
 # post operation hooks.
 #
 ################################################################################

 BR_CARGO_HOME = $(DL_DIR)/br-cargo-home

 PKG_COMMON_CARGO_ENV = \
 	CARGO_HOME=$(BR_CARGO_HOME)

 # __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS is needed to allow
 # passing the -Z target-applies-to-host, which is needed together with
 # CARGO_TARGET_APPLIES_TO_HOST to fix build problems when target
 # architecture == host architecture.

 # __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" is to allow
 # using nighly features on stable releases, i.e features that are not
 # yet considered stable.
 #
 # CARGO_UNSTABLE_HOST_CONFIG="true" enables the host specific
 # configuration feature
 #
 # CARGO_UNSTABLE_TARGET_APPLIES_TO_HOST="true" enables the nightly
 # configuration option target-applies-to-host value to be set
 #
 # CARGO_TARGET_APPLIES_TO_HOST="false" is actually setting the value
 # for this feature, which we disable, to make sure builds where target
 # arch == host arch work correctly
 PKG_CARGO_ENV = \
 	$(PKG_COMMON_CARGO_ENV) \
 	__CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" \
 	CARGO_UNSTABLE_HOST_CONFIG="true" \
 	CARGO_UNSTABLE_TARGET_APPLIES_TO_HOST="true" \
 	CARGO_TARGET_APPLIES_TO_HOST="false" \
 	CARGO_BUILD_TARGET="$(RUSTC_TARGET_NAME)" \
 	CARGO_HOST_RUSTFLAGS="$(addprefix -C link-args=,$(HOST_LDFLAGS))" \
 	CARGO_TARGET_$(call UPPERCASE,$(RUSTC_TARGET_NAME))_LINKER=$(notdir $(TARGET_CROSS))gcc

 # We always set both CARGO_PROFILE_DEV and CARGO_PROFILE_RELEASE
 # as we are unable to select a build profile using the environment.
 #
 # Other cargo profiles generally derive from these two profiles.

 # Disable incremental compilation to match release default.
 #
 # Set codegen-units to release default.
 #
 # Set split-debuginfo to default off for ELF platforms.
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_INCREMENTAL="false" \
 	CARGO_PROFILE_RELEASE_INCREMENTAL="false" \
 	CARGO_PROFILE_DEV_CODEGEN_UNITS="16" \
 	CARGO_PROFILE_RELEASE_CODEGEN_UNITS="16" \
 	CARGO_PROFILE_DEV_SPLIT_DEBUGINFO="off" \
 	CARGO_PROFILE_RELEASE_SPLIT_DEBUGINFO="off"

 # Set the optimization level with the release default as fallback.
 ifeq ($(BR2_OPTIMIZE_0),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="0" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="0"
 else ifeq ($(BR2_OPTIMIZE_1),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="1" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="1"
 else ifeq ($(BR2_OPTIMIZE_2),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="2" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="2"
 else ifeq ($(BR2_OPTIMIZE_3),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
 else ifeq ($(BR2_OPTIMIZE_G),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="0" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="0"
 else ifeq ($(BR2_OPTIMIZE_S),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="s" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="s"
 else ifeq ($(BR2_OPTIMIZE_FAST),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
 else
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
 	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
 endif

 ifeq ($(BR2_ENABLE_LTO),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_LTO="true" \
 	CARGO_PROFILE_RELEASE_LTO="true"
 else
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_LTO="false" \
 	CARGO_PROFILE_RELEASE_LTO="false"
 endif


 ifeq ($(BR2_ENABLE_DEBUG),y)
 ifeq ($(BR2_DEBUG_3),y)
 # full debug info
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_DEBUG="2" \
 	CARGO_PROFILE_RELEASE_DEBUG="2"
 else
 # line tables only
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_DEBUG="1" \
 	CARGO_PROFILE_RELEASE_DEBUG="1"
 endif
 else
 # no debug info
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_DEBUG="0" \
 	CARGO_PROFILE_RELEASE_DEBUG="0"
 endif

 # Enabling debug-assertions enables the runtime debug_assert! macro.
 #
 # Enabling overflow-checks enables runtime panic on integer overflow.
 ifeq ($(BR2_ENABLE_RUNTIME_DEBUG),y)
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_DEBUG_ASSERTIONS="true" \
 	CARGO_PROFILE_RELEASE_DEBUG_ASSERTIONS="true" \
 	CARGO_PROFILE_DEV_OVERFLOW_CHECKS="true" \
 	CARGO_PROFILE_RELEASE_OVERFLOW_CHECKS="true"
 else
 PKG_CARGO_ENV += \
 	CARGO_PROFILE_DEV_DEBUG_ASSERTIONS="false" \
 	CARGO_PROFILE_RELEASE_DEBUG_ASSERTIONS="false" \
 	CARGO_PROFILE_DEV_OVERFLOW_CHECKS="false" \
 	CARGO_PROFILE_RELEASE_OVERFLOW_CHECKS="false"
 endif

 #
 # This is a workaround for https://github.com/rust-lang/compiler-builtins/issues/420
 # and should be removed when fixed upstream
 #
 ifeq ($(NORMALIZED_ARCH),arm)
 	PKG_CARGO_ENV += \
 		CARGO_TARGET_$(call UPPERCASE,$(RUSTC_TARGET_NAME))_RUSTFLAGS="-Clink-arg=-Wl,--allow-multiple-definition"
 endif

 HOST_PKG_CARGO_ENV = \
 	$(PKG_COMMON_CARGO_ENV) \
 	RUSTFLAGS="$(addprefix -C link-args=,$(HOST_LDFLAGS))"

 ################################################################################
 # inner-cargo-package -- defines how the configuration, compilation and
 # installation of a cargo package should be done, implements a few hooks
 # to tune the build process for cargo specifities and calls the generic
 # package infrastructure to generate the necessary make targets
 #
 #  argument 1 is the lowercase package name
 #  argument 2 is the uppercase package name, including a HOST_ prefix
 #             for host packages
 #  argument 3 is the uppercase package name, without the HOST_ prefix
 #             for host packages
 #  argument 4 is the type (target or host)
 ################################################################################

 define inner-cargo-package

 # We need host-rustc to run cargo at download time (for vendoring),
 # and at build and install time.
 $(2)_DOWNLOAD_DEPENDENCIES += host-rustc
 $(2)_DEPENDENCIES += host-rustc

 $(2)_DOWNLOAD_POST_PROCESS = cargo
 $(2)_DL_ENV += CARGO_HOME=$$(BR_CARGO_HOME)

 # If building in a sub directory, use that to find the Cargo.toml
 ifneq ($$($(2)_SUBDIR),)
 $(2)_DL_ENV += BR_CARGO_MANIFEST_PATH=$$($(2)_SUBDIR)/Cargo.toml
 endif

 # Because we append vendored info, we can't rely on the values being empty
 # once we eventually get into the generic-package infra. So, we duplicate
 # the heuristics here
 ifndef $(2)_LICENSE
  ifdef $(3)_LICENSE
   $(2)_LICENSE = $$($(3)_LICENSE)
  endif
 endif

 # Due to vendoring, it is pretty likely that not all licenses are
 # listed in <pkg>_LICENSE. If the license is unset, it is "unknown"
 # so adding unknowns to some unknown is still some other unkown,
 # so don't append the blurb in that case.
 ifneq ($$($(2)_LICENSE),)
 $(2)_LICENSE += , vendored dependencies licenses probably not listed
 endif

 # Note: in all the steps below, we "cd" into the build directory to
 # execute the "cargo" tool instead of passing $(@D)/Cargo.toml as the
 # manifest-path. Indeed while the latter seems to work, it in fact
 # breaks in subtle ways as the way cargo searches for its
 # configuration file is based (among other rules) on the current
 # directory. This means that if cargo is started outside of a package
 # directory, its configuration file will not be taken into account.
 #
 # Also, we pass:
 #  * --offline to prevent cargo from downloading anything: all
 #    dependencies should have been built by the download post
 #    process logic
 #  * --locked to force cargo to use the Cargo.lock file, which ensures
 #    that a fixed set of dependency versions is used

 #
 # Build step. Only define it if not already defined by the package .mk
 # file.
 #
 ifndef $(2)_BUILD_CMDS
 ifeq ($(4),target)
 define $(2)_BUILD_CMDS
 	cd $$($$(PKG)_SRCDIR) && \
 	$$(TARGET_MAKE_ENV) \
 		$$(TARGET_CONFIGURE_OPTS) \
 		$$(PKG_CARGO_ENV) \
 		$$($(2)_CARGO_ENV) \
 		cargo build \
 			--offline \
 			$$(if $$(BR2_ENABLE_DEBUG),,--release) \
 			--manifest-path Cargo.toml \
 			--locked \
 			$$($(2)_CARGO_BUILD_OPTS)
 endef
 else # ifeq ($(4),target)
 define $(2)_BUILD_CMDS
 	cd $$($$(PKG)_SRCDIR) && \
 	$$(HOST_MAKE_ENV) \
 		$$(HOST_CONFIGURE_OPTS) \
 		$$(HOST_PKG_CARGO_ENV) \
 		$$($(2)_CARGO_ENV) \
 		cargo build \
 			--offline \
 			--release \
 			--manifest-path Cargo.toml \
 			--locked \
 			$$($(2)_CARGO_BUILD_OPTS)
 endef
 endif # ifeq ($(4),target)
 endif # ifndef $(2)_BUILD_CMDS

 #
 # Target installation step. Only define it if not already defined by
 # the package .mk file.
 #
 ifndef $(2)_INSTALL_TARGET_CMDS
 define $(2)_INSTALL_TARGET_CMDS
 	cd $$($$(PKG)_SRCDIR) && \
 	$$(TARGET_MAKE_ENV) \
 		$$(TARGET_CONFIGURE_OPTS) \
 		$$(PKG_CARGO_ENV) \
 		$$($(2)_CARGO_ENV) \
 		cargo install \
 			--offline \
 			--root $$(TARGET_DIR)/usr/ \
 			--bins \
 			--path ./ \
 			--force \
 			--locked \
 			-Z target-applies-to-host \
 			$$($(2)_CARGO_INSTALL_OPTS)
 endef
 endif

 ifndef $(2)_INSTALL_CMDS
 define $(2)_INSTALL_CMDS
 	cd $$($$(PKG)_SRCDIR) && \
 	$$(HOST_MAKE_ENV) \
 		$$(HOST_CONFIGURE_OPTS) \
 		$$(HOST_PKG_CARGO_ENV) \
 		$$($(2)_CARGO_ENV) \
 		cargo install \
 			--offline \
 			--root $$(HOST_DIR) \
 			--bins \
 			--path ./ \
 			--force \
 			--locked \
 			$$($(2)_CARGO_INSTALL_OPTS)
 endef
 endif

 # Call the generic package infrastructure to generate the necessary
 # make targets
 $(call inner-generic-package,$(1),$(2),$(3),$(4))

 endef

 ################################################################################
 # cargo-package -- the target generator macro for Cargo packages
 ################################################################################

 cargo-package = $(call inner-cargo-package,$(pkgname),$(call UPPERCASE,$(pkgname)),$(call UPPERCASE,$(pkgname)),target)
 host-cargo-package = $(call inner-cargo-package,host-$(pkgname),$(call UPPERCASE,host-$(pkgname)),$(call UPPERCASE,$(pkgname)),host)
	################################################################################
	# Cargo package infrastructure
	#
	# This file implements an infrastructure that eases development of package
	# .mk files for Cargo packages. It should be used for all packages that use
	# Cargo as their build system.
	#
	# See the Buildroot documentation for details on the usage of this
	# infrastructure
	#
	# In terms of implementation, this Cargo infrastructure requires the .mk file
	# to only specify metadata information about the package: name, version,
	# download URL, etc.
	#
	# We still allow the package .mk file to override what the different steps
	# are doing, if needed. For example, if <PKG>_BUILD_CMDS is already defined,
	# it is used as the list of commands to perform to build the package,
	# instead of the default Cargo behaviour. The package can also define some
	# post operation hooks.
	#
	################################################################################

	BR_CARGO_HOME = $(DL_DIR)/br-cargo-home

	PKG_COMMON_CARGO_ENV = \
	CARGO_HOME=$(BR_CARGO_HOME)

	# __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS is needed to allow
	# passing the -Z target-applies-to-host, which is needed together with
	# CARGO_TARGET_APPLIES_TO_HOST to fix build problems when target
	# architecture == host architecture.

	# __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" is to allow
	# using nighly features on stable releases, i.e features that are not
	# yet considered stable.
	#
	# CARGO_UNSTABLE_HOST_CONFIG="true" enables the host specific
	# configuration feature
	#
	# CARGO_UNSTABLE_TARGET_APPLIES_TO_HOST="true" enables the nightly
	# configuration option target-applies-to-host value to be set
	#
	# CARGO_TARGET_APPLIES_TO_HOST="false" is actually setting the value
	# for this feature, which we disable, to make sure builds where target
	# arch == host arch work correctly
	PKG_CARGO_ENV = \
	$(PKG_COMMON_CARGO_ENV) \
	__CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" \
	CARGO_UNSTABLE_HOST_CONFIG="true" \
	CARGO_UNSTABLE_TARGET_APPLIES_TO_HOST="true" \
	CARGO_TARGET_APPLIES_TO_HOST="false" \
	CARGO_BUILD_TARGET="$(RUSTC_TARGET_NAME)" \
	CARGO_HOST_RUSTFLAGS="$(addprefix -C link-args=,$(HOST_LDFLAGS))" \
	CARGO_TARGET_$(call UPPERCASE,$(RUSTC_TARGET_NAME))_LINKER=$(notdir $(TARGET_CROSS))gcc

	# We always set both CARGO_PROFILE_DEV and CARGO_PROFILE_RELEASE
	# as we are unable to select a build profile using the environment.
	#
	# Other cargo profiles generally derive from these two profiles.

	# Disable incremental compilation to match release default.
	#
	# Set codegen-units to release default.
	#
	# Set split-debuginfo to default off for ELF platforms.
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_INCREMENTAL="false" \
	CARGO_PROFILE_RELEASE_INCREMENTAL="false" \
	CARGO_PROFILE_DEV_CODEGEN_UNITS="16" \
	CARGO_PROFILE_RELEASE_CODEGEN_UNITS="16" \
	CARGO_PROFILE_DEV_SPLIT_DEBUGINFO="off" \
	CARGO_PROFILE_RELEASE_SPLIT_DEBUGINFO="off"

	# Set the optimization level with the release default as fallback.
	ifeq ($(BR2_OPTIMIZE_0),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="0" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="0"
	else ifeq ($(BR2_OPTIMIZE_1),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="1" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="1"
	else ifeq ($(BR2_OPTIMIZE_2),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="2" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="2"
	else ifeq ($(BR2_OPTIMIZE_3),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
	else ifeq ($(BR2_OPTIMIZE_G),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="0" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="0"
	else ifeq ($(BR2_OPTIMIZE_S),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="s" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="s"
	else ifeq ($(BR2_OPTIMIZE_FAST),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
	else
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_OPT_LEVEL="3" \
	CARGO_PROFILE_RELEASE_OPT_LEVEL="3"
	endif

	ifeq ($(BR2_ENABLE_LTO),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_LTO="true" \
	CARGO_PROFILE_RELEASE_LTO="true"
	else
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_LTO="false" \
	CARGO_PROFILE_RELEASE_LTO="false"
	endif


	ifeq ($(BR2_ENABLE_DEBUG),y)
	ifeq ($(BR2_DEBUG_3),y)
	# full debug info
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_DEBUG="2" \
	CARGO_PROFILE_RELEASE_DEBUG="2"
	else
	# line tables only
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_DEBUG="1" \
	CARGO_PROFILE_RELEASE_DEBUG="1"
	endif
	else
	# no debug info
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_DEBUG="0" \
	CARGO_PROFILE_RELEASE_DEBUG="0"
	endif

	# Enabling debug-assertions enables the runtime debug_assert! macro.
	#
	# Enabling overflow-checks enables runtime panic on integer overflow.
	ifeq ($(BR2_ENABLE_RUNTIME_DEBUG),y)
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_DEBUG_ASSERTIONS="true" \
	CARGO_PROFILE_RELEASE_DEBUG_ASSERTIONS="true" \
	CARGO_PROFILE_DEV_OVERFLOW_CHECKS="true" \
	CARGO_PROFILE_RELEASE_OVERFLOW_CHECKS="true"
	else
	PKG_CARGO_ENV += \
	CARGO_PROFILE_DEV_DEBUG_ASSERTIONS="false" \
	CARGO_PROFILE_RELEASE_DEBUG_ASSERTIONS="false" \
	CARGO_PROFILE_DEV_OVERFLOW_CHECKS="false" \
	CARGO_PROFILE_RELEASE_OVERFLOW_CHECKS="false"
	endif

	#
	# This is a workaround for https://github.com/rust-lang/compiler-builtins/issues/420
	# and should be removed when fixed upstream
	#
	ifeq ($(NORMALIZED_ARCH),arm)
	PKG_CARGO_ENV += \
	CARGO_TARGET_$(call UPPERCASE,$(RUSTC_TARGET_NAME))_RUSTFLAGS="-Clink-arg=-Wl,--allow-multiple-definition"
	endif

	HOST_PKG_CARGO_ENV = \
	$(PKG_COMMON_CARGO_ENV) \
	RUSTFLAGS="$(addprefix -C link-args=,$(HOST_LDFLAGS))"

	################################################################################
	# inner-cargo-package -- defines how the configuration, compilation and
	# installation of a cargo package should be done, implements a few hooks
	# to tune the build process for cargo specifities and calls the generic
	# package infrastructure to generate the necessary make targets
	#
	# argument 1 is the lowercase package name
	# argument 2 is the uppercase package name, including a HOST_ prefix
	# for host packages
	# argument 3 is the uppercase package name, without the HOST_ prefix
	# for host packages
	# argument 4 is the type (target or host)
	################################################################################

	define inner-cargo-package

	# We need host-rustc to run cargo at download time (for vendoring),
	# and at build and install time.
	$(2)_DOWNLOAD_DEPENDENCIES += host-rustc
	$(2)_DEPENDENCIES += host-rustc

	$(2)_DOWNLOAD_POST_PROCESS = cargo
	$(2)_DL_ENV += CARGO_HOME=$$(BR_CARGO_HOME)

	# If building in a sub directory, use that to find the Cargo.toml
	ifneq ($$($(2)_SUBDIR),)
	$(2)_DL_ENV += BR_CARGO_MANIFEST_PATH=$$($(2)_SUBDIR)/Cargo.toml
	endif

	# Because we append vendored info, we can't rely on the values being empty
	# once we eventually get into the generic-package infra. So, we duplicate
	# the heuristics here
	ifndef $(2)_LICENSE
	ifdef $(3)_LICENSE
	$(2)_LICENSE = $$($(3)_LICENSE)
	endif
	endif

	# Due to vendoring, it is pretty likely that not all licenses are
	# listed in <pkg>_LICENSE. If the license is unset, it is "unknown"
	# so adding unknowns to some unknown is still some other unkown,
	# so don't append the blurb in that case.
	ifneq ($$($(2)_LICENSE),)
	$(2)_LICENSE += , vendored dependencies licenses probably not listed
	endif

	# Note: in all the steps below, we "cd" into the build directory to
	# execute the "cargo" tool instead of passing $(@D)/Cargo.toml as the
	# manifest-path. Indeed while the latter seems to work, it in fact
	# breaks in subtle ways as the way cargo searches for its
	# configuration file is based (among other rules) on the current
	# directory. This means that if cargo is started outside of a package
	# directory, its configuration file will not be taken into account.
	#
	# Also, we pass:
	# * --offline to prevent cargo from downloading anything: all
	# dependencies should have been built by the download post
	# process logic
	# * --locked to force cargo to use the Cargo.lock file, which ensures
	# that a fixed set of dependency versions is used

	#
	# Build step. Only define it if not already defined by the package .mk
	# file.
	#
	ifndef $(2)_BUILD_CMDS
	ifeq ($(4),target)
	define $(2)_BUILD_CMDS
	cd $$($$(PKG)_SRCDIR) && \
	$$(TARGET_MAKE_ENV) \
	$$(TARGET_CONFIGURE_OPTS) \
	$$(PKG_CARGO_ENV) \
	$$($(2)_CARGO_ENV) \
	cargo build \
	--offline \
	$$(if $$(BR2_ENABLE_DEBUG),,--release) \
	--manifest-path Cargo.toml \
	--locked \
	$$($(2)_CARGO_BUILD_OPTS)
	endef
	else # ifeq ($(4),target)
	define $(2)_BUILD_CMDS
	cd $$($$(PKG)_SRCDIR) && \
	$$(HOST_MAKE_ENV) \
	$$(HOST_CONFIGURE_OPTS) \
	$$(HOST_PKG_CARGO_ENV) \
	$$($(2)_CARGO_ENV) \
	cargo build \
	--offline \
	--release \
	--manifest-path Cargo.toml \
	--locked \
	$$($(2)_CARGO_BUILD_OPTS)
	endef
	endif # ifeq ($(4),target)
	endif # ifndef $(2)_BUILD_CMDS

	#
	# Target installation step. Only define it if not already defined by
	# the package .mk file.
	#
	ifndef $(2)_INSTALL_TARGET_CMDS
	define $(2)_INSTALL_TARGET_CMDS
	cd $$($$(PKG)_SRCDIR) && \
	$$(TARGET_MAKE_ENV) \
	$$(TARGET_CONFIGURE_OPTS) \
	$$(PKG_CARGO_ENV) \
	$$($(2)_CARGO_ENV) \
	cargo install \
	--offline \
	--root $$(TARGET_DIR)/usr/ \
	--bins \
	--path ./ \
	--force \
	--locked \
	-Z target-applies-to-host \
	$$($(2)_CARGO_INSTALL_OPTS)
	endef
	endif

	ifndef $(2)_INSTALL_CMDS
	define $(2)_INSTALL_CMDS
	cd $$($$(PKG)_SRCDIR) && \
	$$(HOST_MAKE_ENV) \
	$$(HOST_CONFIGURE_OPTS) \
	$$(HOST_PKG_CARGO_ENV) \
	$$($(2)_CARGO_ENV) \
	cargo install \
	--offline \
	--root $$(HOST_DIR) \
	--bins \
	--path ./ \
	--force \
	--locked \
	$$($(2)_CARGO_INSTALL_OPTS)
	endef
	endif

	# Call the generic package infrastructure to generate the necessary
	# make targets
	$(call inner-generic-package,$(1),$(2),$(3),$(4))

	endef

	################################################################################
	# cargo-package -- the target generator macro for Cargo packages
	################################################################################

	cargo-package = $(call inner-cargo-package,$(pkgname),$(call UPPERCASE,$(pkgname)),$(call UPPERCASE,$(pkgname)),target)
	host-cargo-package = $(call inner-cargo-package,host-$(pkgname),$(call UPPERCASE,host-$(pkgname)),$(call UPPERCASE,$(pkgname)),host)