eclass/cros-go.eclass - mirrors/cros/chromiumos/overlays/chromiumos-overlay - Git at Google

 # Copyright 2015-2018 The Chromium OS Authors. All rights reserved.
 # Distributed under the terms of the GNU General Public License v2

 # @ECLASS: cros-go.eclass
 # @MAINTAINER:
 # The Chromium OS Authors <chromium-os-dev@chromium.org>
 # @BUGREPORTS:
 # Please report bugs via https://crbug.com/new (with component "Tools>ChromeOS-Toolchain")
 # @VCSURL: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/eclass/@ECLASS@
 # @BLURB: Eclass for fetching, building, and installing Go packages.
 # @DESCRIPTION:
 # See http://www.chromium.org/chromium-os/developer-guide/go-in-chromium-os for details.

 # @ECLASS-VARIABLE: CROS_GO_SOURCE
 # @PRE_INHERIT
 # @DESCRIPTION:
 # Path to the upstream repository and commit id.
 # Go repositories on "github.com" and "*.googlesource.com" are supported.
 # The source string contains the path of the git repository containing Go
 # packages, and a commit-id (or version tag).
 # For example:
 #   CROS_GO_SOURCE="github.com/golang/glog 44145f04b68cf362d9c4df2182967c2275eaefed"
 # will fetch the sources from https://github.com/golang/glog at the
 # specified commit-id, and
 #   CROS_GO_SOURCE="github.com/pkg/errors v0.8.0"
 # will fetch the sources from https://github.com/pkg/errors at version
 # v0.8.0.
 # By default, the import path for Go packages in the repository is the
 # same as repository path. This can be overridden by appending a colon
 # to the repository path, followed by an alternate import path.
 # For example:
 #   CROS_GO_SOURCE="github.com/go-yaml/yaml:gopkg.in/yaml.v2 v2.2.1"
 # will fetch the sources from https://github.com/go-yaml/yaml at version
 # v2.2.1, and install the package under "gopkg.in/yaml.v2".
 # CROS_GO_SOURCE can contain multiple items when defined as an array:
 #   CROS_GO_SOURCE=(
 #     "github.com/golang/glog 44145f04b68cf362d9c4df2182967c2275eaefed"
 #     "github.com/pkg/errors v0.8.0"
 #     "github.com/go-yaml/yaml:gopkg.in/yaml.v2 v2.2.1"
 #   )

 # @ECLASS-VARIABLE: CROS_GO_WORKSPACE
 # @DESCRIPTION:
 # Path to the Go workspace, default is ${S}.
 # The Go workspace is searched for packages to build and install.
 # If all Go packages in a repository are located under "go/src/":
 #   CROS_GO_WORKSPACE="${S}/go"
 # CROS_GO_WORKSPACE can contain multiple items when defined as an array:
 #   CROS_GO_WORKSPACE=(
 #     "${S}"
 #     "${S}/tast-base"
 #   )

 # @ECLASS-VARIABLE: CROS_GO_BINARIES
 # @DESCRIPTION:
 # Go programs to build and install.
 # Each program is specified by the path of a directory that
 # contains a package "main", or a single Go source file which
 # must also contain the package "main". For directories, the
 # last component of the package path becomes the name of the
 # executable.  For files, the ".go" suffix is also stripped.
 # The executable name can be overridden by appending a colon
 # to the package path, followed by an alternate name.
 # The install path for an executable can be overridden by
 # appending a colon to the package path, followed by the
 # desired install path/name for it.
 # For example:
 #   CROS_GO_BINARIES=(
 #     "golang.org/x/tools/cmd/godoc"
 #     "golang.org/x/tools/cmd/guru:goguru"
 #     "golang.org/x/tools/cmd/stringer:/usr/local/bin/gostringer"
 #     "golang.org/x/tools/cmd/foo.go"
 #     "golang.org/x/tools/cmd/foo.go:gofoo"
 #   )
 # builds and installs "godoc", "goguru", "gostringer", "foo"
 # and "gofoo" binaries.

 # Helper function for path and names used in cros-go_src_{compile,install}.
 # Returns various views of the information in a CROS_GO_BINARIES entry (a
 # "specification" or "spec") separated by colons.
 parse_binspec() {
 	local spec="$1"
 	# Split spec at colon into source and override.
 	local source
 	local override
 	IFS=: read source override empty <<<"${spec}"
 	test -z "${empty}" || die "bad CROS_GO_BINARIES entry: \"${spec}\""
 	local target
 	local installdir
 	if [[ -z "${override}" ]] ; then
 		target="${spec##*/}"
 		# if there is no override, remove .go suffix (if any).
 		target="${target%%.go}"
 		installdir="/usr/bin"
 	else
 		# target is the last component of the override path
 		target="${override##*/}"
 		installdir="${override%/*}"
 	fi
 	# if the source is a single go file, use its full path name
 	if [[ "${source##*.}" == "go" ]]; then
 		source="${S}/src/${source}"
 	fi
 	# there is no colon in any variable, so colon is a safe separator
 	echo "${source}:${target}:${installdir}"
 }

 # @ECLASS-VARIABLE: CROS_GO_VERSION
 # @DESCRIPTION:
 # Version string to embed in the executable binary.
 # The variable main.Version is set to this value at build time.
 # For example:
 #   CROS_GO_VERSION="${PVR}"
 # will set main.Version string variable to package version and
 # revision (if any) of the ebuild.

 # @ECLASS-VARIABLE: CROS_GO_PACKAGES
 # @DESCRIPTION:
 # Go packages to install in /usr/lib/gopath.
 # Packages are installed in /usr/lib/gopath such that they
 # can be imported later from Go code using the exact paths
 # listed here. For example:
 #   CROS_GO_PACKAGES=(
 #     "github.com/golang/glog"
 #   )
 # will install package files to
 #   "/usr/lib/gopath/src/github.com/golang/glog"
 # and other Go projects can use the package with
 #   import "github.com/golang/glog"
 # If the last component of a package path is "...", it is
 # expanded to include all Go packages under the directory.

 # @ECLASS-VARIABLE: CROS_GO_TEST
 # @DESCRIPTION:
 # Go packages to test.
 # Package tests are run with "-short" flag by default.
 # Package tests are always built and run locally on host.
 # Default is to test all packages in CROS_GO_WORKSPACE(s).
 : ${CROS_GO_TEST:=./...}

 # @ECLASS-VARIABLE: CROS_GO_VET
 # @DESCRIPTION:
 # Go packages to check using "go vet".
 # As in CROS_GO_PACKAGES, "..." is expanded.

 # @ECLASS-VARIABLE: CROS_GO_VET_FLAGS
 # @DESCRIPTION:
 # Flags to pass to "go vet" if CROS_GO_VET is set.
 # See https://golang.org/cmd/vet/ for available flags.

 inherit toolchain-funcs

 DEPEND="dev-lang/go"

 # @FUNCTION: cros-go_get
 # @USAGE: <source> [variables to extract]
 # @INTERNAL
 # @DESCRIPTION:
 # Parse source string and extract different components.
 # This function parses the string containing upstream
 # repository, import path, and commit id information
 # (see description of CROS_GO_SOURCE format above).
 # It can also be used to construct the name of the
 # distfile and a uri for fetching it.
 cros-go_get() {
 	local src commit repopath importpath distfile uri
 	src="$1"
 	commit="${src##* }"
 	repopath="${src%% *}"
 	importpath="${repopath#*:}"
 	repopath="${repopath%:*}"
 	distfile="${repopath//\//-}-${commit}.tar.gz"
 	uri="https://${repopath}/${commit}.tar.gz"
 	case "${repopath%%/*}" in
 		github.com)
 			uri="https://${repopath}/archive/${commit}.tar.gz" ;;
 		*.googlesource.com)
 			uri="https://${repopath}/+archive/${commit}.tar.gz" ;;
 		*)
 			die "Unsupported upstream source in ${repopath}" ;;
 	esac

 	shift
 	local arg
 	for arg in "$@" ; do
 		case "${arg}" in
 			commit) printf "%s" "${commit}" ;;
 			repopath) printf "%s" "${repopath}" ;;
 			importpath) printf "%s" "${importpath}" ;;
 			distfile) printf "%s" "${distfile}" ;;
 			uri) printf "%s" "${uri}" ;;
 			*) printf "${arg}" ;;
 		esac
 	done
 }

 # @FUNCTION: cros-go_src_uri
 # @RETURN: a valid SRC_URI for CROS_GO_SOURCE
 # @DESCRIPTION:
 # Set the SRC_URI in an ebuild with:
 #   SRC_URI="$(cros-go_src_uri)"
 cros-go_src_uri() {
 	local src
 	for src in "${CROS_GO_SOURCE[@]}" ; do
 		cros-go_get "${src}" uri " -> " distfile "\n"
 	done
 }

 # @FUNCTION: cros-go_pkg_nofetch
 # @DESCRIPTION:
 # Print useful information on how to download a source tarball and
 # add it to chromeos-localmirror.
 cros-go_pkg_nofetch() {
 	local src
 	for src in "${CROS_GO_SOURCE[@]}" ; do
 		local uri="$(cros-go_get "${src}" uri)"
 		local distfile="$(cros-go_get "${src}" distfile)"
 		einfo "Run these commands to add ${distfile} to chromeos-localmirror:"
 		einfo "  wget -O ${distfile} ${uri}"
 		einfo "  gsutil cp -a public-read ${distfile} gs://chromeos-localmirror/distfiles/"
 		einfo
 	done
 	einfo "After all distfiles have been mirrored, update the 'Manifest' file with:"
 	einfo "  ebuild ${EBUILD} manifest"
 }

 # @FUNCTION: cros-go_src_unpack
 # @DESCRIPTION:
 # Unpack the source tarball under appropriate location based on
 # the desired import path.
 cros-go_src_unpack() {
 	local src
 	for src in "${CROS_GO_SOURCE[@]}" ; do
 		local commit="$(cros-go_get "${src}" commit)"
 		local repopath="$(cros-go_get "${src}" repopath)"
 		local importpath="$(cros-go_get "${src}" importpath)"
 		local distfile="$(cros-go_get "${src}" distfile)"

 		local destdir="${S}/src/${importpath}"
 		case "${repopath%%/*}" in
 			github.com)
 				# Unpacking tarballs from github creates a top level
 				# directory "projectname-version", so extra logic is
 				# required to make the contents appear correctly in
 				# the desired destination directory.
 				mkdir -p "${destdir%/*}" || die
 				pushd "${destdir%/*}" >/dev/null || die
 				unpack "${distfile}"
 				mv "${repopath##*/}-${commit#v}" "${importpath##*/}" || die
 				popd >/dev/null || die
 				;;
 			*.googlesource.com)
 				mkdir -p "${destdir}" || die
 				pushd "${destdir}" >/dev/null || die
 				unpack "${distfile}"
 				popd >/dev/null || die
 				;;
 		esac
 	done
 }

 # @FUNCTION: cros-go_workspace
 # @RETURN: Go workspaces, colon separated
 # @INTERNAL
 # @DESCRIPTION:
 # Return the list of workspaces in CROS_GO_WORKSPACE,
 # properly formatted for inclusion into GOPATH.
 cros-go_workspace() {
 	if [[ ${#CROS_GO_WORKSPACE[@]} != 0 ]] ; then
 		( IFS=:; echo "${CROS_GO_WORKSPACE[*]}" )
 	else
 		echo "${S}"
 	fi
 }

 # @FUNCTION: cros-go_gopath
 # @RETURN: a valid GOPATH for CROS_GO_WORKSPACE
 # @DESCRIPTION:
 # Set the GOPATH in an ebuild with:
 #   GOPATH="$(cros-go_gopath)"
 cros-go_gopath() {
 	echo "$(cros-go_workspace):${SYSROOT}/usr/lib/gopath"
 }

 # @FUNCTION: cros_go
 # @DESCRIPTION:
 # Wrapper function for invoking the Go tool from an ebuild.
 # Sets up GOPATH, and uses the appropriate cross-compiler.
 cros_go() {
 	GOPATH="$(cros-go_gopath)" $(tc-getGO) "$@" || die
 }

 # @FUNCTION: go_list
 # @DESCRIPTION:
 # List all Go packages matching a pattern.
 # Only list packages in the current workspace.
 go_list() {
 	GOPATH="$(cros-go_workspace)" $(tc-getGO) list "$@" || die
 }

 # @FUNCTION: go_test
 # @DESCRIPTION:
 # Wrapper function for building and running unit tests.
 # Package tests are always built and run locally on host.
 go_test() {
 	GOPATH="$(cros-go_gopath)" $(tc-getBUILD_GO) test "$@" || die
 }

 # @FUNCTION: go_vet
 # @DESCRIPTION:
 # Wrapper function for running "go vet".
 go_vet() {
 	GOPATH="$(cros-go_gopath)" $(tc-getBUILD_GO) vet \
 		"${CROS_GO_VET_FLAGS[@]}" "$@" || die
 }

 # @FUNCTION: cros-go_src_compile
 # @DESCRIPTION:
 # Build CROS_GO_BINARIES.
 cros-go_src_compile() {
 	local bin
 	local source
 	local target
 	local installdir
 	for bin in "${CROS_GO_BINARIES[@]}" ; do
 		einfo "Building \"${bin}\""
 		IFS=: read source target installdir <<<"$(parse_binspec "${bin}")"
 		cros_go build -v \
 			${CROS_GO_VERSION:+"-ldflags=-X main.Version=${CROS_GO_VERSION}"} \
 			-o "${target}" \
 			"${source}"
 	done

 	local pkg
 	for pkg in "${CROS_GO_VET[@]}" ; do
 		einfo "Vetting \"${pkg}\""
 		go_vet "${pkg}"
 	done
 }

 # @FUNCTION: cros-go_src_test
 # @DESCRIPTION:
 # Run tests for packages listed in CROS_GO_TEST.
 cros-go_src_test() {
 	local pkglist=( $(go_list "${CROS_GO_TEST[@]}") )
 	go_test -short "${pkglist[@]}"
 }

 # @FUNCTION: cros-go_src_install
 # @DESCRIPTION:
 # Install CROS_GO_BINARIES and CROS_GO_PACKAGES.
 cros-go_src_install() {
 	# Install the compiled binaries.
 	local bin
 	local source
 	local target
 	local installdir
 	for bin in "${CROS_GO_BINARIES[@]}" ; do
 		einfo "Installing \"${bin}\""
 		IFS=: read source target installdir <<<"$(parse_binspec "${bin}")"
 		(
 			# Run in sub-shell so we do not modify env.
 			exeinto "${installdir}"
 			doexe "${target}"
 		)
 	done

 	# Install the importable packages in /usr/lib/gopath.
 	local pkglist=()
 	if [[ ${#CROS_GO_PACKAGES[@]} != 0 ]] ; then
 		pkglist=( $(go_list "${CROS_GO_PACKAGES[@]}") )
 	fi
 	local pkg
 	for pkg in "${pkglist[@]}" ; do
 		einfo "Installing \"${pkg}\""
 		local pkgdir="$(go_list -f "{{.Dir}}" "${pkg}")"
 		(
 			# Run in sub-shell so we do not modify env.
 			insinto "/usr/lib/gopath/src/${pkg}"
 			local file
 			while read -d $'\0' -r file ; do
 				doins "${file}"
 			done < <(find "${pkgdir}" -maxdepth 1 ! -type d -print0)
 		)
 	done
 }

 # @FUNCTION: cros-go_pkg_postinst
 # @DESCRIPTION:
 # Check for missing dependencies of installed packages.
 cros-go_pkg_postinst() {
 	# This only works if we're building and installing from source.
 	[[ "${MERGE_TYPE}" == "source" ]] || return

 	# Get the list of packages from the workspace in ${S}.
 	local pkglist=()
 	if [[ ${#CROS_GO_PACKAGES[@]} != 0 ]] ; then
 		pkglist=( $(go_list "${CROS_GO_PACKAGES[@]}") )
 	fi

 	# Switch the workspace to where the packages were installed.
 	local CROS_GO_WORKSPACE="${SYSROOT}/usr/lib/gopath"

 	# For each installed package, check for missing dependencies.
 	local pkg
 	for pkg in "${pkglist[@]}" ; do
 		if [[ $(go_list -f "{{.Incomplete}}" "${pkg}") == "true" ]] ; then
 			go_list -f "{{.DepsErrors}}" "${pkg}"
 			die "Package has missing dependency: \"${pkg}\""
 		fi
 	done
 }

 if [[ ${#CROS_GO_SOURCE[@]} != 0 ]] ; then
 	EXPORT_FUNCTIONS pkg_nofetch src_unpack
 fi

 EXPORT_FUNCTIONS src_compile src_test src_install pkg_postinst
	# Copyright 2015-2018 The Chromium OS Authors. All rights reserved.
	# Distributed under the terms of the GNU General Public License v2

	# @ECLASS: cros-go.eclass
	# @MAINTAINER:
	# The Chromium OS Authors <chromium-os-dev@chromium.org>
	# @BUGREPORTS:
	# Please report bugs via https://crbug.com/new (with component "Tools>ChromeOS-Toolchain")
	# @VCSURL: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/eclass/@ECLASS@
	# @BLURB: Eclass for fetching, building, and installing Go packages.
	# @DESCRIPTION:
	# See http://www.chromium.org/chromium-os/developer-guide/go-in-chromium-os for details.

	# @ECLASS-VARIABLE: CROS_GO_SOURCE
	# @PRE_INHERIT
	# @DESCRIPTION:
	# Path to the upstream repository and commit id.
	# Go repositories on "github.com" and "*.googlesource.com" are supported.
	# The source string contains the path of the git repository containing Go
	# packages, and a commit-id (or version tag).
	# For example:
	# CROS_GO_SOURCE="github.com/golang/glog 44145f04b68cf362d9c4df2182967c2275eaefed"
	# will fetch the sources from https://github.com/golang/glog at the
	# specified commit-id, and
	# CROS_GO_SOURCE="github.com/pkg/errors v0.8.0"
	# will fetch the sources from https://github.com/pkg/errors at version
	# v0.8.0.
	# By default, the import path for Go packages in the repository is the
	# same as repository path. This can be overridden by appending a colon
	# to the repository path, followed by an alternate import path.
	# For example:
	# CROS_GO_SOURCE="github.com/go-yaml/yaml:gopkg.in/yaml.v2 v2.2.1"
	# will fetch the sources from https://github.com/go-yaml/yaml at version
	# v2.2.1, and install the package under "gopkg.in/yaml.v2".
	# CROS_GO_SOURCE can contain multiple items when defined as an array:
	# CROS_GO_SOURCE=(
	# "github.com/golang/glog 44145f04b68cf362d9c4df2182967c2275eaefed"
	# "github.com/pkg/errors v0.8.0"
	# "github.com/go-yaml/yaml:gopkg.in/yaml.v2 v2.2.1"
	# )

	# @ECLASS-VARIABLE: CROS_GO_WORKSPACE
	# @DESCRIPTION:
	# Path to the Go workspace, default is ${S}.
	# The Go workspace is searched for packages to build and install.
	# If all Go packages in a repository are located under "go/src/":
	# CROS_GO_WORKSPACE="${S}/go"
	# CROS_GO_WORKSPACE can contain multiple items when defined as an array:
	# CROS_GO_WORKSPACE=(
	# "${S}"
	# "${S}/tast-base"
	# )

	# @ECLASS-VARIABLE: CROS_GO_BINARIES
	# @DESCRIPTION:
	# Go programs to build and install.
	# Each program is specified by the path of a directory that
	# contains a package "main", or a single Go source file which
	# must also contain the package "main". For directories, the
	# last component of the package path becomes the name of the
	# executable. For files, the ".go" suffix is also stripped.
	# The executable name can be overridden by appending a colon
	# to the package path, followed by an alternate name.
	# The install path for an executable can be overridden by
	# appending a colon to the package path, followed by the
	# desired install path/name for it.
	# For example:
	# CROS_GO_BINARIES=(
	# "golang.org/x/tools/cmd/godoc"
	# "golang.org/x/tools/cmd/guru:goguru"
	# "golang.org/x/tools/cmd/stringer:/usr/local/bin/gostringer"
	# "golang.org/x/tools/cmd/foo.go"
	# "golang.org/x/tools/cmd/foo.go:gofoo"
	# )
	# builds and installs "godoc", "goguru", "gostringer", "foo"
	# and "gofoo" binaries.

	# Helper function for path and names used in cros-go_src_{compile,install}.
	# Returns various views of the information in a CROS_GO_BINARIES entry (a
	# "specification" or "spec") separated by colons.
	parse_binspec() {
	local spec="$1"
	# Split spec at colon into source and override.
	local source
	local override
	IFS=: read source override empty <<<"${spec}"
	test -z "${empty}" \|\| die "bad CROS_GO_BINARIES entry: \"${spec}\""
	local target
	local installdir
	if [[ -z "${override}" ]] ; then
	target="${spec##*/}"
	# if there is no override, remove .go suffix (if any).
	target="${target%%.go}"
	installdir="/usr/bin"
	else
	# target is the last component of the override path
	target="${override##*/}"
	installdir="${override%/*}"
	fi
	# if the source is a single go file, use its full path name
	if [[ "${source##*.}" == "go" ]]; then
	source="${S}/src/${source}"
	fi
	# there is no colon in any variable, so colon is a safe separator
	echo "${source}:${target}:${installdir}"
	}

	# @ECLASS-VARIABLE: CROS_GO_VERSION
	# @DESCRIPTION:
	# Version string to embed in the executable binary.
	# The variable main.Version is set to this value at build time.
	# For example:
	# CROS_GO_VERSION="${PVR}"
	# will set main.Version string variable to package version and
	# revision (if any) of the ebuild.

	# @ECLASS-VARIABLE: CROS_GO_PACKAGES
	# @DESCRIPTION:
	# Go packages to install in /usr/lib/gopath.
	# Packages are installed in /usr/lib/gopath such that they
	# can be imported later from Go code using the exact paths
	# listed here. For example:
	# CROS_GO_PACKAGES=(
	# "github.com/golang/glog"
	# )
	# will install package files to
	# "/usr/lib/gopath/src/github.com/golang/glog"
	# and other Go projects can use the package with
	# import "github.com/golang/glog"
	# If the last component of a package path is "...", it is
	# expanded to include all Go packages under the directory.

	# @ECLASS-VARIABLE: CROS_GO_TEST
	# @DESCRIPTION:
	# Go packages to test.
	# Package tests are run with "-short" flag by default.
	# Package tests are always built and run locally on host.
	# Default is to test all packages in CROS_GO_WORKSPACE(s).
	: ${CROS_GO_TEST:=./...}

	# @ECLASS-VARIABLE: CROS_GO_VET
	# @DESCRIPTION:
	# Go packages to check using "go vet".
	# As in CROS_GO_PACKAGES, "..." is expanded.

	# @ECLASS-VARIABLE: CROS_GO_VET_FLAGS
	# @DESCRIPTION:
	# Flags to pass to "go vet" if CROS_GO_VET is set.
	# See https://golang.org/cmd/vet/ for available flags.

	inherit toolchain-funcs

	DEPEND="dev-lang/go"

	# @FUNCTION: cros-go_get
	# @USAGE: <source> [variables to extract]
	# @INTERNAL
	# @DESCRIPTION:
	# Parse source string and extract different components.
	# This function parses the string containing upstream
	# repository, import path, and commit id information
	# (see description of CROS_GO_SOURCE format above).
	# It can also be used to construct the name of the
	# distfile and a uri for fetching it.
	cros-go_get() {
	local src commit repopath importpath distfile uri
	src="$1"
	commit="${src##* }"
	repopath="${src%% *}"
	importpath="${repopath#*:}"
	repopath="${repopath%:*}"
	distfile="${repopath//\//-}-${commit}.tar.gz"
	uri="https://${repopath}/${commit}.tar.gz"
	case "${repopath%%/*}" in
	github.com)
	uri="https://${repopath}/archive/${commit}.tar.gz" ;;
	*.googlesource.com)
	uri="https://${repopath}/+archive/${commit}.tar.gz" ;;
	*)
	die "Unsupported upstream source in ${repopath}" ;;
	esac

	shift
	local arg
	for arg in "$@" ; do
	case "${arg}" in
	commit) printf "%s" "${commit}" ;;
	repopath) printf "%s" "${repopath}" ;;
	importpath) printf "%s" "${importpath}" ;;
	distfile) printf "%s" "${distfile}" ;;
	uri) printf "%s" "${uri}" ;;
	*) printf "${arg}" ;;
	esac
	done
	}

	# @FUNCTION: cros-go_src_uri
	# @RETURN: a valid SRC_URI for CROS_GO_SOURCE
	# @DESCRIPTION:
	# Set the SRC_URI in an ebuild with:
	# SRC_URI="$(cros-go_src_uri)"
	cros-go_src_uri() {
	local src
	for src in "${CROS_GO_SOURCE[@]}" ; do
	cros-go_get "${src}" uri " -> " distfile "\n"
	done
	}

	# @FUNCTION: cros-go_pkg_nofetch
	# @DESCRIPTION:
	# Print useful information on how to download a source tarball and
	# add it to chromeos-localmirror.
	cros-go_pkg_nofetch() {
	local src
	for src in "${CROS_GO_SOURCE[@]}" ; do
	local uri="$(cros-go_get "${src}" uri)"
	local distfile="$(cros-go_get "${src}" distfile)"
	einfo "Run these commands to add ${distfile} to chromeos-localmirror:"
	einfo " wget -O ${distfile} ${uri}"
	einfo " gsutil cp -a public-read ${distfile} gs://chromeos-localmirror/distfiles/"
	einfo
	done
	einfo "After all distfiles have been mirrored, update the 'Manifest' file with:"
	einfo " ebuild ${EBUILD} manifest"
	}

	# @FUNCTION: cros-go_src_unpack
	# @DESCRIPTION:
	# Unpack the source tarball under appropriate location based on
	# the desired import path.
	cros-go_src_unpack() {
	local src
	for src in "${CROS_GO_SOURCE[@]}" ; do
	local commit="$(cros-go_get "${src}" commit)"
	local repopath="$(cros-go_get "${src}" repopath)"
	local importpath="$(cros-go_get "${src}" importpath)"
	local distfile="$(cros-go_get "${src}" distfile)"

	local destdir="${S}/src/${importpath}"
	case "${repopath%%/*}" in
	github.com)
	# Unpacking tarballs from github creates a top level
	# directory "projectname-version", so extra logic is
	# required to make the contents appear correctly in
	# the desired destination directory.
	mkdir -p "${destdir%/*}" \|\| die
	pushd "${destdir%/*}" >/dev/null \|\| die
	unpack "${distfile}"
	mv "${repopath##/}-${commit#v}" "${importpath##/}" \|\| die
	popd >/dev/null \|\| die
	;;
	*.googlesource.com)
	mkdir -p "${destdir}" \|\| die
	pushd "${destdir}" >/dev/null \|\| die
	unpack "${distfile}"
	popd >/dev/null \|\| die
	;;
	esac
	done
	}

	# @FUNCTION: cros-go_workspace
	# @RETURN: Go workspaces, colon separated
	# @INTERNAL
	# @DESCRIPTION:
	# Return the list of workspaces in CROS_GO_WORKSPACE,
	# properly formatted for inclusion into GOPATH.
	cros-go_workspace() {
	if [[ ${#CROS_GO_WORKSPACE[@]} != 0 ]] ; then
	( IFS=:; echo "${CROS_GO_WORKSPACE[*]}" )
	else
	echo "${S}"
	fi
	}

	# @FUNCTION: cros-go_gopath
	# @RETURN: a valid GOPATH for CROS_GO_WORKSPACE
	# @DESCRIPTION:
	# Set the GOPATH in an ebuild with:
	# GOPATH="$(cros-go_gopath)"
	cros-go_gopath() {
	echo "$(cros-go_workspace):${SYSROOT}/usr/lib/gopath"
	}

	# @FUNCTION: cros_go
	# @DESCRIPTION:
	# Wrapper function for invoking the Go tool from an ebuild.
	# Sets up GOPATH, and uses the appropriate cross-compiler.
	cros_go() {
	GOPATH="$(cros-go_gopath)" $(tc-getGO) "$@" \|\| die
	}

	# @FUNCTION: go_list
	# @DESCRIPTION:
	# List all Go packages matching a pattern.
	# Only list packages in the current workspace.
	go_list() {
	GOPATH="$(cros-go_workspace)" $(tc-getGO) list "$@" \|\| die
	}

	# @FUNCTION: go_test
	# @DESCRIPTION:
	# Wrapper function for building and running unit tests.
	# Package tests are always built and run locally on host.
	go_test() {
	GOPATH="$(cros-go_gopath)" $(tc-getBUILD_GO) test "$@" \|\| die
	}

	# @FUNCTION: go_vet
	# @DESCRIPTION:
	# Wrapper function for running "go vet".
	go_vet() {
	GOPATH="$(cros-go_gopath)" $(tc-getBUILD_GO) vet \
	"${CROS_GO_VET_FLAGS[@]}" "$@" \|\| die
	}

	# @FUNCTION: cros-go_src_compile
	# @DESCRIPTION:
	# Build CROS_GO_BINARIES.
	cros-go_src_compile() {
	local bin
	local source
	local target
	local installdir
	for bin in "${CROS_GO_BINARIES[@]}" ; do
	einfo "Building \"${bin}\""
	IFS=: read source target installdir <<<"$(parse_binspec "${bin}")"
	cros_go build -v \
	${CROS_GO_VERSION:+"-ldflags=-X main.Version=${CROS_GO_VERSION}"} \
	-o "${target}" \
	"${source}"
	done

	local pkg
	for pkg in "${CROS_GO_VET[@]}" ; do
	einfo "Vetting \"${pkg}\""
	go_vet "${pkg}"
	done
	}

	# @FUNCTION: cros-go_src_test
	# @DESCRIPTION:
	# Run tests for packages listed in CROS_GO_TEST.
	cros-go_src_test() {
	local pkglist=( $(go_list "${CROS_GO_TEST[@]}") )
	go_test -short "${pkglist[@]}"
	}

	# @FUNCTION: cros-go_src_install
	# @DESCRIPTION:
	# Install CROS_GO_BINARIES and CROS_GO_PACKAGES.
	cros-go_src_install() {
	# Install the compiled binaries.
	local bin
	local source
	local target
	local installdir
	for bin in "${CROS_GO_BINARIES[@]}" ; do
	einfo "Installing \"${bin}\""
	IFS=: read source target installdir <<<"$(parse_binspec "${bin}")"
	(
	# Run in sub-shell so we do not modify env.
	exeinto "${installdir}"
	doexe "${target}"
	)
	done

	# Install the importable packages in /usr/lib/gopath.
	local pkglist=()
	if [[ ${#CROS_GO_PACKAGES[@]} != 0 ]] ; then
	pkglist=( $(go_list "${CROS_GO_PACKAGES[@]}") )
	fi
	local pkg
	for pkg in "${pkglist[@]}" ; do
	einfo "Installing \"${pkg}\""
	local pkgdir="$(go_list -f "{{.Dir}}" "${pkg}")"
	(
	# Run in sub-shell so we do not modify env.
	insinto "/usr/lib/gopath/src/${pkg}"
	local file
	while read -d $'\0' -r file ; do
	doins "${file}"
	done < <(find "${pkgdir}" -maxdepth 1 ! -type d -print0)
	)
	done
	}

	# @FUNCTION: cros-go_pkg_postinst
	# @DESCRIPTION:
	# Check for missing dependencies of installed packages.
	cros-go_pkg_postinst() {
	# This only works if we're building and installing from source.
	[[ "${MERGE_TYPE}" == "source" ]] \|\| return

	# Get the list of packages from the workspace in ${S}.
	local pkglist=()
	if [[ ${#CROS_GO_PACKAGES[@]} != 0 ]] ; then
	pkglist=( $(go_list "${CROS_GO_PACKAGES[@]}") )
	fi

	# Switch the workspace to where the packages were installed.
	local CROS_GO_WORKSPACE="${SYSROOT}/usr/lib/gopath"

	# For each installed package, check for missing dependencies.
	local pkg
	for pkg in "${pkglist[@]}" ; do
	if [[ $(go_list -f "{{.Incomplete}}" "${pkg}") == "true" ]] ; then
	go_list -f "{{.DepsErrors}}" "${pkg}"
	die "Package has missing dependency: \"${pkg}\""
	fi
	done
	}

	if [[ ${#CROS_GO_SOURCE[@]} != 0 ]] ; then
	EXPORT_FUNCTIONS pkg_nofetch src_unpack
	fi

	EXPORT_FUNCTIONS src_compile src_test src_install pkg_postinst