scripts/bazel-complete-template.bash - bazel - Git at Google

 # -*- sh -*- (Bash only)
 #
 # Copyright 2015 The Bazel Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #    http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 #
 # Bash completion of Bazel commands.
 #
 # The template is expanded at build time using tables of commands/options
 # derived from the bazel executable built in the same client; the expansion is
 # written to bazel-complete.bash.
 #
 # Provides command-completion for:
 # - bazel prefix options (e.g. --host_jvm_args)
 # - blaze command-set (e.g. build, test)
 # - blaze command-specific options (e.g. --copts)
 # - values for enum-valued options
 # - package-names, exploring all package-path roots.
 # - targets within packages.

 # The package path used by the completion routines.  Unfortunately
 # this isn't necessarily the same as the actual package path used by
 # Bazel, but that's ok.  (It's impossible for us to reliably know what
 # the relevant package-path, so this is just a good guess.  Users can
 # override it if they want.)
 #
 # Don't use it directly. Generate the final script with
 # bazel build //scripts:bash_completion instead.
 #
 : ${BAZEL_COMPLETION_PACKAGE_PATH:=%workspace%}


 # If true, Bazel query is used for autocompletion.  This is more
 # accurate than the heuristic grep, especially for strangely-formatted
 # BUILD files.  But it can be slower, especially if the Bazel server
 # is busy, and more brittle, if the BUILD file contains serious
 # errors.   This is an experimental feature.
 : ${BAZEL_COMPLETION_USE_QUERY:=false}


 # If true, Bazel run allows autocompletion for test targets. This is convenient
 # for users who run a lot of tests/benchmarks locally with blaze run.
 : ${BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN:=false}

 # Some commands might interfer with the important one, so don't complete them
 : ${BAZEL_IGNORED_COMMAND_REGEX:="__none__"}

 # bazel & ibazel commands
 : ${BAZEL:=bazel}
 : ${IBAZEL:=ibazel}

 # Pattern to match for looking for a target
 #  BAZEL_BUILD_MATCH_PATTERN__* give the pattern for label-*
 #  when looking in the the build file.
 #  BAZEL_QUERY_MATCH_PATTERN__* give the pattern for label-*
 #  when using 'bazel query'.
 # _RUNTEST are special case when BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN
 # is on.
 : ${BAZEL_BUILD_MATCH_PATTERN__test:='(.*_test|test_suite)'}
 : ${BAZEL_QUERY_MATCH_PATTERN__test:='(test|test_suite)'}
 : ${BAZEL_BUILD_MATCH_PATTERN__bin:='.*_binary'}
 : ${BAZEL_QUERY_MATCH_PATTERN__bin:='(binary)'}
 : ${BAZEL_BUILD_MATCH_PATTERN_RUNTEST__bin:='(.*_(binary|test)|test_suite)'}
 : ${BAZEL_QUERY_MATCH_PATTERN_RUNTEST__bin:='(binary|test)'}
 : ${BAZEL_BUILD_MATCH_PATTERN__:='.*'}
 : ${BAZEL_QUERY_MATCH_PATTERN__:=''}

 # Usage: _bazel__get_rule_match_pattern <command>
 # Determine what kind of rules to match, based on command.
 _bazel__get_rule_match_pattern() {
   local var_name pattern
   if _bazel__is_true "$BAZEL_COMPLETION_USE_QUERY"; then
     var_name="BAZEL_QUERY_MATCH_PATTERN"
   else
     var_name="BAZEL_BUILD_MATCH_PATTERN"
   fi
   if [[ "$1" =~ ^label-?([a-z]*)$ ]]; then
     pattern=${BASH_REMATCH[1]:-}
     if _bazel__is_true "$BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN"; then
       eval "echo \"\${${var_name}_RUNTEST__${pattern}:-\$${var_name}__${pattern}}\""
     else
       eval "echo \"\$${var_name}__${pattern}\""
     fi
   fi
 }

 # Compute workspace directory. Search for the innermost
 # enclosing directory with a WORKSPACE file.
 _bazel__get_workspace_path() {
   local workspace=$PWD
   while true; do
     if [ -f "${workspace}/WORKSPACE" ]; then
       break
     elif [ -z "$workspace" -o "$workspace" = "/" ]; then
       workspace=$PWD
       break;
     fi
     workspace=${workspace%/*}
   done
   echo $workspace
 }


 # Find the current piece of the line to complete, but only do word breaks at
 # certain characters. In particular, ignore these: "':=
 # This method also takes into account the current cursor position.
 #
 # Works with both bash 3 and 4! Bash 3 and 4 perform different word breaks when
 # computing the COMP_WORDS array. We need this here because Bazel options are of
 # the form --a=b, and labels of the form //some/label:target.
 _bazel__get_cword() {
   local cur=${COMP_LINE:0:$COMP_POINT}
   # This expression finds the last word break character, as defined in the
   # COMP_WORDBREAKS variable, but without '=' or ':', which is not preceeded by
   # a slash. Quote characters are also excluded.
   local wordbreaks="$COMP_WORDBREAKS"
   wordbreaks="${wordbreaks//\'/}"
   wordbreaks="${wordbreaks//\"/}"
   wordbreaks="${wordbreaks//:/}"
   wordbreaks="${wordbreaks//=/}"
   local word_start=$(expr "$cur" : '.*[^\]['"${wordbreaks}"']')
   echo "${cur:$word_start}"
 }


 # Usage: _bazel__package_path <workspace> <displacement>
 #
 # Prints a list of package-path root directories, displaced using the
 # current displacement from the workspace.  All elements have a
 # trailing slash.
 _bazel__package_path() {
   local workspace=$1 displacement=$2 root
   IFS=:
   for root in ${BAZEL_COMPLETION_PACKAGE_PATH//\%workspace\%/$workspace}; do
     unset IFS
     echo "$root/$displacement"
   done
 }

 # Usage: _bazel__options_for <command>
 #
 # Prints the set of options for a given Bazel command, e.g. "build".
 _bazel__options_for() {
   local options
   if [[ "${BAZEL_COMMAND_LIST}" =~ ^(.* )?$1( .*)?$ ]]; then
       # assumes option names only use ASCII characters
       local option_name=$(echo $1 | tr a-z A-Z | tr "-" "_")
       eval "echo \${BAZEL_COMMAND_${option_name}_FLAGS}" | tr " " "\n"
   fi
 }
 # Usage: _bazel__expansion_for <command>
 #
 # Prints the completion pattern for a given Bazel command, e.g. "build".
 _bazel__expansion_for() {
   local options
   if [[ "${BAZEL_COMMAND_LIST}" =~ ^(.* )?$1( .*)?$ ]]; then
       # assumes option names only use ASCII characters
       local option_name=$(echo $1 | tr a-z A-Z | tr "-" "_")
       eval "echo \${BAZEL_COMMAND_${option_name}_ARGUMENT}"
   fi
 }

 # Usage: _bazel__matching_targets <kind> <prefix>
 #
 # Prints target names of kind <kind> and starting with <prefix> in the BUILD
 # file given as standard input.  <kind> is a basic regex (BRE) used to match the
 # bazel rule kind and <prefix> is the prefix of the target name.
 _bazel__matching_targets() {
   local kind_pattern="$1"
   local target_prefix="$2"
   # The following commands do respectively:
   #   Remove BUILD file comments
   #   Replace \n by spaces to have the BUILD file in a single line
   #   Extract all rule types and target names
   #   Grep the kind pattern and the target prefix
   #   Returns the target name
   sed 's/#.*$//' \
       | tr "\n" " " \
       | sed 's/\([a-zA-Z0-9_]*\) *(\([^)]* \)\{0,1\}name *= *['\''"]\([a-zA-Z0-9_/.+=,@~-]*\)['\''"][^)]*)/\
 type:\1 name:\3\
 /g' \
       | "grep" -E "^type:$kind_pattern name:$target_prefix" \
       | cut -d ':' -f 3
 }


 # Usage: _bazel__is_true <string>
 #
 # Returns true or false based on the input string. The following are
 # valid true values (the rest are false): "1", "true".
 _bazel__is_true() {
   local str="$1"
   [[ "$str" == "1" || "$str" == "true" ]]
 }

 # Usage: _bazel__expand_rules_in_package <workspace> <displacement>
 #                                        <current> <label-type>
 #
 # Expands rules in specified packages, exploring all roots of
 # $BAZEL_COMPLETION_PACKAGE_PATH, not just $(pwd).  Only rules
 # appropriate to the command are printed.  Sets $COMPREPLY array to
 # result.
 #
 # If $BAZEL_COMPLETION_USE_QUERY is true, 'bazel query' is used
 # instead, with the actual Bazel package path;
 # $BAZEL_COMPLETION_PACKAGE_PATH is ignored in this case, since the
 # actual Bazel value is likely to be more accurate.
 _bazel__expand_rules_in_package() {
   local workspace=$1 displacement=$2 current=$3 label_type=$4
   local package_name=$(echo "$current" | cut -f1 -d:)
   local rule_prefix=$(echo "$current" | cut -f2 -d:)
   local root buildfile rule_pattern r result

   result=
   pattern=$(_bazel__get_rule_match_pattern "$label_type")
   if _bazel__is_true "$BAZEL_COMPLETION_USE_QUERY"; then
     package_name=$(echo "$package_name" | tr -d "'\"") # remove quotes
     result=$(${BAZEL} --output_base=/tmp/${BAZEL}-completion-$USER query \
                    --keep_going --noshow_progress \
       "kind('$pattern rule', '$package_name:*')" 2>/dev/null |
       cut -f2 -d: | "grep" "^$rule_prefix")
   else
     for root in $(_bazel__package_path "$workspace" "$displacement"); do
       buildfile="$root/$package_name/BUILD.bazel"
       if [ ! -f "$buildfile" ]; then
         buildfile="$root/$package_name/BUILD"
       fi
       if [ -f "$buildfile" ]; then
         result=$(_bazel__matching_targets \
                    "$pattern" "$rule_prefix" <"$buildfile")
         break
       fi
     done
   fi

   index=$(echo $result | wc -w)
   if [ -n "$result" ]; then
       echo "$result" | tr " " "\n" | sed 's|$| |'
   fi
   # Include ":all" wildcard if there was no unique match.  (The zero
   # case is tricky: we need to include "all" in that case since
   # otherwise we won't expand "a" to "all" in the absence of rules
   # starting with "a".)
   if [ $index -ne 1 ] && expr all : "\\($rule_prefix\\)" >/dev/null; then
     echo "all "
   fi
 }

 # Usage: _bazel__expand_package_name <workspace> <displacement> <current-word>
 #                                    <label-type>
 #
 # Expands directories, but explores all roots of
 # BAZEL_COMPLETION_PACKAGE_PATH, not just $(pwd).  When a directory is
 # a bazel package, the completion offers "pkg:" so you can expand
 # inside the package.
 # Sets $COMPREPLY array to result.
 _bazel__expand_package_name() {
   local workspace=$1 displacement=$2 current=$3 type=${4:-} root dir index
   for root in $(_bazel__package_path "$workspace" "$displacement"); do
     found=0
     for dir in $(compgen -d $root$current); do
       [ -L "$dir" ] && continue  # skip symlinks (e.g. bazel-bin)
       [[ "$dir" =~ ^(.*/)?\.[^/]*$ ]] && continue  # skip dotted dir (e.g. .git)
       found=1
       echo "${dir#$root}/"
       if [ -f $dir/BUILD.bazel -o -f $dir/BUILD ]; then
         if [ "${type}" = "label-package" ]; then
           echo "${dir#$root} "
         else
           echo "${dir#$root}:"
         fi
       fi
     done
     [ $found -gt 0 ] && break  # Stop searching package path upon first match.
   done
 }

 # Usage: _bazel__expand_target_pattern <workspace> <displacement>
 #                                      <word> <label-syntax>
 #
 # Expands "word" to match target patterns, using the current workspace
 # and displacement from it.  "command" is used to filter rules.
 # Sets $COMPREPLY array to result.
 _bazel__expand_target_pattern() {
   local workspace=$1 displacement=$2 current=$3 label_syntax=$4
   case "$current" in
     //*:*) # Expand rule names within package, no displacement.
       if [ "${label_syntax}" = "label-package" ]; then
         compgen -S " " -W "BUILD" "$(echo current | cut -f ':' -d2)"
       else
         _bazel__expand_rules_in_package "$workspace" "" "$current" "$label_syntax"
       fi
       ;;
     *:*) # Expand rule names within package, displaced.
       if [ "${label_syntax}" = "label-package" ]; then
         compgen -S " " -W "BUILD" "$(echo current | cut -f ':' -d2)"
       else
         _bazel__expand_rules_in_package \
           "$workspace" "$displacement" "$current" "$label_syntax"
       fi
       ;;
     //*) # Expand filenames using package-path, no displacement
       _bazel__expand_package_name "$workspace" "" "$current" "$label_syntax"
       ;;
     *) # Expand filenames using package-path, displaced.
       if [ -n "$current" ]; then
         _bazel__expand_package_name "$workspace" "$displacement" "$current" "$label_syntax"
       fi
       ;;
   esac
 }

 _bazel__get_command() {
   for word in "${COMP_WORDS[@]:1:COMP_CWORD-1}"; do
     if echo "$BAZEL_COMMAND_LIST" | "grep" -wsq -e "$word"; then
       echo $word
       break
     fi
   done
 }

 # Returns the displacement to the workspace given in $1
 _bazel__get_displacement() {
   if [[ "$PWD" =~ ^$1/.*$ ]]; then
     echo ${PWD##$1/}/
   fi
 }


 # Usage: _bazel__complete_pattern <workspace> <displacement> <current>
 #                                 <type>
 #
 # Expand a word according to a type. The currently supported types are:
 #  - {a,b,c}: an enum that can take value a, b or c
 #  - label: a label of any kind
 #  - label-bin: a label to a runnable rule (basically to a _binary rule)
 #  - label-test: a label to a test rule
 #  - info-key: an info key as listed by `bazel help info-keys`
 #  - command: the name of a command
 #  - path: a file path
 #  - combinaison of previous type using | as separator
 _bazel__complete_pattern() {
   local workspace=$1 displacement=$2 current=$3 types=$4
   for type in $(echo $types | tr "|" "\n"); do
     case "$type" in
       label*)
         _bazel__expand_target_pattern "$workspace" "$displacement" \
             "$current" "$type"
         ;;
       info-key)
     compgen -S " " -W "${BAZEL_INFO_KEYS}" -- "$current"
         ;;
       "command")
         local commands=$(echo "${BAZEL_COMMAND_LIST}" \
           | tr " " "\n" | "grep" -v "^${BAZEL_IGNORED_COMMAND_REGEX}$")
     compgen -S " " -W "${commands}" -- "$current"
         ;;
       path)
         compgen -f -- "$current"
         ;;
       *)
         compgen -S " " -W "$type" -- "$current"
         ;;
     esac
   done
 }

 # Usage: _bazel__expand_options <workspace> <displacement> <current-word>
 #                               <options>
 #
 # Expands options, making sure that if current-word contains an equals sign,
 # it is handled appropriately.
 _bazel__expand_options() {
   local workspace="$1" displacement="$2" cur="$3" options="$4"
   if [[ $cur =~ = ]]; then
     # also expands special labels
     current=$(echo "$cur" | cut -f2 -d=)
     _bazel__complete_pattern "$workspace" "$displacement" "$current" \
     "$(compgen -W "$options" -- "$cur" | cut -f2 -d=)" \
         | sort -u
   else
     compgen -W "$(echo "$options" | sed 's|=.*$|=|')" -- "$cur" \
     | sed 's|\([^=]\)$|\1 |'
   fi
 }


 _bazel__complete_stdout() {
   local cur=$(_bazel__get_cword) word command displacement workspace

   # Determine command: "" (startup-options) or one of $BAZEL_COMMAND_LIST.
   command="$(_bazel__get_command)"

   workspace="$(_bazel__get_workspace_path)"
   displacement="$(_bazel__get_displacement ${workspace})"

   case "$command" in
     "") # Expand startup-options or commands
       local commands=$(echo "${BAZEL_COMMAND_LIST}" \
         | tr " " "\n" | "grep" -v "^${BAZEL_IGNORED_COMMAND_REGEX}$")
       _bazel__expand_options  "$workspace" "$displacement" "$cur" \
           "${commands}\
           ${BAZEL_STARTUP_OPTIONS}"
       ;;

     *)
       case "$cur" in
         -*) # Expand options:
           _bazel__expand_options  "$workspace" "$displacement" "$cur" \
               "$(_bazel__options_for $command)"
           ;;
         *)  # Expand target pattern
       expansion_pattern="$(_bazel__expansion_for $command)"
           NON_QUOTE_REGEX="^[\"']"
           if [[ $command = query && $cur =~ $NON_QUOTE_REGEX ]]; then
             : # Ideally we would expand query expressions---it's not
               # that hard, conceptually---but readline is just too
               # damn complex when it comes to quotation.  Instead,
               # for query, we just expand target patterns, unless
               # the first char is a quote.
           elif [ -n "$expansion_pattern" ]; then
             _bazel__complete_pattern \
         "$workspace" "$displacement" "$cur" "$expansion_pattern"
           fi
           ;;
       esac
       ;;
   esac
 }

 _bazel__to_compreply() {
   local replies="$1"
   COMPREPLY=()
   # Trick to preserve whitespaces
   while IFS="" read -r reply; do
     COMPREPLY+=("${reply}")
   done < <(echo "${replies}")
 }

 _bazel__complete() {
   _bazel__to_compreply "$(_bazel__complete_stdout)"
 }

 # Some users have aliases such as bt="bazel test" or bb="bazel build", this
 # completion function allows them to have auto-completion for these aliases.
 _bazel__complete_target_stdout() {
   local cur=$(_bazel__get_cword) word command displacement workspace

   # Determine command: "" (startup-options) or one of $BAZEL_COMMAND_LIST.
   command="$1"

   workspace="$(_bazel__get_workspace_path)"
   displacement="$(_bazel__get_displacement ${workspace})"

   _bazel__to_compreply "$(_bazel__expand_target_pattern "$workspace" "$displacement" \
       "$cur" "$(_bazel__expansion_for $command)")"
 }

 # default completion for bazel
 complete -F _bazel__complete -o nospace "${BAZEL}"
 complete -F _bazel__complete -o nospace "${IBAZEL}"
	# -- sh -- (Bash only)
	#
	# Copyright 2015 The Bazel Authors. All rights reserved.
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.
	#
	#
	# Bash completion of Bazel commands.
	#
	# The template is expanded at build time using tables of commands/options
	# derived from the bazel executable built in the same client; the expansion is
	# written to bazel-complete.bash.
	#
	# Provides command-completion for:
	# - bazel prefix options (e.g. --host_jvm_args)
	# - blaze command-set (e.g. build, test)
	# - blaze command-specific options (e.g. --copts)
	# - values for enum-valued options
	# - package-names, exploring all package-path roots.
	# - targets within packages.

	# The package path used by the completion routines. Unfortunately
	# this isn't necessarily the same as the actual package path used by
	# Bazel, but that's ok. (It's impossible for us to reliably know what
	# the relevant package-path, so this is just a good guess. Users can
	# override it if they want.)
	#
	# Don't use it directly. Generate the final script with
	# bazel build //scripts:bash_completion instead.
	#
	: ${BAZEL_COMPLETION_PACKAGE_PATH:=%workspace%}


	# If true, Bazel query is used for autocompletion. This is more
	# accurate than the heuristic grep, especially for strangely-formatted
	# BUILD files. But it can be slower, especially if the Bazel server
	# is busy, and more brittle, if the BUILD file contains serious
	# errors. This is an experimental feature.
	: ${BAZEL_COMPLETION_USE_QUERY:=false}


	# If true, Bazel run allows autocompletion for test targets. This is convenient
	# for users who run a lot of tests/benchmarks locally with blaze run.
	: ${BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN:=false}

	# Some commands might interfer with the important one, so don't complete them
	: ${BAZEL_IGNORED_COMMAND_REGEX:="__none__"}

	# bazel & ibazel commands
	: ${BAZEL:=bazel}
	: ${IBAZEL:=ibazel}

	# Pattern to match for looking for a target
	# BAZEL_BUILD_MATCH_PATTERN__* give the pattern for label-*
	# when looking in the the build file.
	# BAZEL_QUERY_MATCH_PATTERN__* give the pattern for label-*
	# when using 'bazel query'.
	# _RUNTEST are special case when BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN
	# is on.
	: ${BAZEL_BUILD_MATCH_PATTERN__test:='(.*_test\|test_suite)'}
	: ${BAZEL_QUERY_MATCH_PATTERN__test:='(test\|test_suite)'}
	: ${BAZEL_BUILD_MATCH_PATTERN__bin:='.*_binary'}
	: ${BAZEL_QUERY_MATCH_PATTERN__bin:='(binary)'}
	: ${BAZEL_BUILD_MATCH_PATTERN_RUNTEST__bin:='(.*_(binary\|test)\|test_suite)'}
	: ${BAZEL_QUERY_MATCH_PATTERN_RUNTEST__bin:='(binary\|test)'}
	: ${BAZEL_BUILD_MATCH_PATTERN__:='.*'}
	: ${BAZEL_QUERY_MATCH_PATTERN__:=''}

	# Usage: _bazel__get_rule_match_pattern <command>
	# Determine what kind of rules to match, based on command.
	_bazel__get_rule_match_pattern() {
	local var_name pattern
	if _bazel__is_true "$BAZEL_COMPLETION_USE_QUERY"; then
	var_name="BAZEL_QUERY_MATCH_PATTERN"
	else
	var_name="BAZEL_BUILD_MATCH_PATTERN"
	fi
	if [[ "$1" =~ ^label-?([a-z]*)$ ]]; then
	pattern=${BASH_REMATCH[1]:-}
	if _bazel__is_true "$BAZEL_COMPLETION_ALLOW_TESTS_FOR_RUN"; then
	eval "echo \"\${${var_name}_RUNTEST__${pattern}:-\$${var_name}__${pattern}}\""
	else
	eval "echo \"\$${var_name}__${pattern}\""
	fi
	fi
	}

	# Compute workspace directory. Search for the innermost
	# enclosing directory with a WORKSPACE file.
	_bazel__get_workspace_path() {
	local workspace=$PWD
	while true; do
	if [ -f "${workspace}/WORKSPACE" ]; then
	break
	elif [ -z "$workspace" -o "$workspace" = "/" ]; then
	workspace=$PWD
	break;
	fi
	workspace=${workspace%/*}
	done
	echo $workspace
	}


	# Find the current piece of the line to complete, but only do word breaks at
	# certain characters. In particular, ignore these: "':=
	# This method also takes into account the current cursor position.
	#
	# Works with both bash 3 and 4! Bash 3 and 4 perform different word breaks when
	# computing the COMP_WORDS array. We need this here because Bazel options are of
	# the form --a=b, and labels of the form //some/label:target.
	_bazel__get_cword() {
	local cur=${COMP_LINE:0:$COMP_POINT}
	# This expression finds the last word break character, as defined in the
	# COMP_WORDBREAKS variable, but without '=' or ':', which is not preceeded by
	# a slash. Quote characters are also excluded.
	local wordbreaks="$COMP_WORDBREAKS"
	wordbreaks="${wordbreaks//\'/}"
	wordbreaks="${wordbreaks//\"/}"
	wordbreaks="${wordbreaks//:/}"
	wordbreaks="${wordbreaks//=/}"
	local word_start=$(expr "$cur" : '.*[^\]['"${wordbreaks}"']')
	echo "${cur:$word_start}"
	}


	# Usage: _bazel__package_path <workspace> <displacement>
	#
	# Prints a list of package-path root directories, displaced using the
	# current displacement from the workspace. All elements have a
	# trailing slash.
	_bazel__package_path() {
	local workspace=$1 displacement=$2 root
	IFS=:
	for root in ${BAZEL_COMPLETION_PACKAGE_PATH//\%workspace\%/$workspace}; do
	unset IFS
	echo "$root/$displacement"
	done
	}

	# Usage: _bazel__options_for <command>
	#
	# Prints the set of options for a given Bazel command, e.g. "build".
	_bazel__options_for() {
	local options
	if [[ "${BAZEL_COMMAND_LIST}" =~ ^(.* )?$1( .*)?$ ]]; then
	# assumes option names only use ASCII characters
	local option_name=$(echo $1 \| tr a-z A-Z \| tr "-" "_")
	eval "echo \${BAZEL_COMMAND_${option_name}_FLAGS}" \| tr " " "\n"
	fi
	}
	# Usage: _bazel__expansion_for <command>
	#
	# Prints the completion pattern for a given Bazel command, e.g. "build".
	_bazel__expansion_for() {
	local options
	if [[ "${BAZEL_COMMAND_LIST}" =~ ^(.* )?$1( .*)?$ ]]; then
	# assumes option names only use ASCII characters
	local option_name=$(echo $1 \| tr a-z A-Z \| tr "-" "_")
	eval "echo \${BAZEL_COMMAND_${option_name}_ARGUMENT}"
	fi
	}

	# Usage: _bazel__matching_targets <kind> <prefix>
	#
	# Prints target names of kind <kind> and starting with <prefix> in the BUILD
	# file given as standard input. <kind> is a basic regex (BRE) used to match the
	# bazel rule kind and <prefix> is the prefix of the target name.
	_bazel__matching_targets() {
	local kind_pattern="$1"
	local target_prefix="$2"
	# The following commands do respectively:
	# Remove BUILD file comments
	# Replace \n by spaces to have the BUILD file in a single line
	# Extract all rule types and target names
	# Grep the kind pattern and the target prefix
	# Returns the target name
	sed 's/#.*$//' \
	\| tr "\n" " " \
	\| sed 's/\([a-zA-Z0-9_]\) (\([^)]* \)\{0,1\}name = ['\''"]\([a-zA-Z0-9_/.+=,@~-]\)['\''"][^)])/\
	type:\1 name:\3\
	/g' \
	\| "grep" -E "^type:$kind_pattern name:$target_prefix" \
	\| cut -d ':' -f 3
	}


	# Usage: _bazel__is_true <string>
	#
	# Returns true or false based on the input string. The following are
	# valid true values (the rest are false): "1", "true".
	_bazel__is_true() {
	local str="$1"
	[[ "$str" == "1" \|\| "$str" == "true" ]]
	}

	# Usage: _bazel__expand_rules_in_package <workspace> <displacement>
	# <current> <label-type>
	#
	# Expands rules in specified packages, exploring all roots of
	# $BAZEL_COMPLETION_PACKAGE_PATH, not just $(pwd). Only rules
	# appropriate to the command are printed. Sets $COMPREPLY array to
	# result.
	#
	# If $BAZEL_COMPLETION_USE_QUERY is true, 'bazel query' is used
	# instead, with the actual Bazel package path;
	# $BAZEL_COMPLETION_PACKAGE_PATH is ignored in this case, since the
	# actual Bazel value is likely to be more accurate.
	_bazel__expand_rules_in_package() {
	local workspace=$1 displacement=$2 current=$3 label_type=$4
	local package_name=$(echo "$current" \| cut -f1 -d:)
	local rule_prefix=$(echo "$current" \| cut -f2 -d:)
	local root buildfile rule_pattern r result

	result=
	pattern=$(_bazel__get_rule_match_pattern "$label_type")
	if _bazel__is_true "$BAZEL_COMPLETION_USE_QUERY"; then
	package_name=$(echo "$package_name" \| tr -d "'\"") # remove quotes
	result=$(${BAZEL} --output_base=/tmp/${BAZEL}-completion-$USER query \
	--keep_going --noshow_progress \
	"kind('$pattern rule', '$package_name:*')" 2>/dev/null \|
	cut -f2 -d: \| "grep" "^$rule_prefix")
	else
	for root in $(_bazel__package_path "$workspace" "$displacement"); do
	buildfile="$root/$package_name/BUILD.bazel"
	if [ ! -f "$buildfile" ]; then
	buildfile="$root/$package_name/BUILD"
	fi
	if [ -f "$buildfile" ]; then
	result=$(_bazel__matching_targets \
	"$pattern" "$rule_prefix" <"$buildfile")
	break
	fi
	done
	fi

	index=$(echo $result \| wc -w)
	if [ -n "$result" ]; then
	echo "$result" \| tr " " "\n" \| sed 's\|$\| \|'
	fi
	# Include ":all" wildcard if there was no unique match. (The zero
	# case is tricky: we need to include "all" in that case since
	# otherwise we won't expand "a" to "all" in the absence of rules
	# starting with "a".)
	if [ $index -ne 1 ] && expr all : "\\($rule_prefix\\)" >/dev/null; then
	echo "all "
	fi
	}

	# Usage: _bazel__expand_package_name <workspace> <displacement> <current-word>
	# <label-type>
	#
	# Expands directories, but explores all roots of
	# BAZEL_COMPLETION_PACKAGE_PATH, not just $(pwd). When a directory is
	# a bazel package, the completion offers "pkg:" so you can expand
	# inside the package.
	# Sets $COMPREPLY array to result.
	_bazel__expand_package_name() {
	local workspace=$1 displacement=$2 current=$3 type=${4:-} root dir index
	for root in $(_bazel__package_path "$workspace" "$displacement"); do
	found=0
	for dir in $(compgen -d $root$current); do
	[ -L "$dir" ] && continue # skip symlinks (e.g. bazel-bin)
	[[ "$dir" =~ ^(./)?\.[^/]$ ]] && continue # skip dotted dir (e.g. .git)
	found=1
	echo "${dir#$root}/"
	if [ -f $dir/BUILD.bazel -o -f $dir/BUILD ]; then
	if [ "${type}" = "label-package" ]; then
	echo "${dir#$root} "
	else
	echo "${dir#$root}:"
	fi
	fi
	done
	[ $found -gt 0 ] && break # Stop searching package path upon first match.
	done
	}

	# Usage: _bazel__expand_target_pattern <workspace> <displacement>
	# <word> <label-syntax>
	#
	# Expands "word" to match target patterns, using the current workspace
	# and displacement from it. "command" is used to filter rules.
	# Sets $COMPREPLY array to result.
	_bazel__expand_target_pattern() {
	local workspace=$1 displacement=$2 current=$3 label_syntax=$4
	case "$current" in
	//:) # Expand rule names within package, no displacement.
	if [ "${label_syntax}" = "label-package" ]; then
	compgen -S " " -W "BUILD" "$(echo current \| cut -f ':' -d2)"
	else
	_bazel__expand_rules_in_package "$workspace" "" "$current" "$label_syntax"
	fi
	;;
	:) # Expand rule names within package, displaced.
	if [ "${label_syntax}" = "label-package" ]; then
	compgen -S " " -W "BUILD" "$(echo current \| cut -f ':' -d2)"
	else
	_bazel__expand_rules_in_package \
	"$workspace" "$displacement" "$current" "$label_syntax"
	fi
	;;
	//*) # Expand filenames using package-path, no displacement
	_bazel__expand_package_name "$workspace" "" "$current" "$label_syntax"
	;;
	*) # Expand filenames using package-path, displaced.
	if [ -n "$current" ]; then
	_bazel__expand_package_name "$workspace" "$displacement" "$current" "$label_syntax"
	fi
	;;
	esac
	}

	_bazel__get_command() {
	for word in "${COMP_WORDS[@]:1:COMP_CWORD-1}"; do
	if echo "$BAZEL_COMMAND_LIST" \| "grep" -wsq -e "$word"; then
	echo $word
	break
	fi
	done
	}

	# Returns the displacement to the workspace given in $1
	_bazel__get_displacement() {
	if [[ "$PWD" =~ ^$1/.*$ ]]; then
	echo ${PWD##$1/}/
	fi
	}


	# Usage: _bazel__complete_pattern <workspace> <displacement> <current>
	# <type>
	#
	# Expand a word according to a type. The currently supported types are:
	# - {a,b,c}: an enum that can take value a, b or c
	# - label: a label of any kind
	# - label-bin: a label to a runnable rule (basically to a _binary rule)
	# - label-test: a label to a test rule
	# - info-key: an info key as listed by `bazel help info-keys`
	# - command: the name of a command
	# - path: a file path
	# - combinaison of previous type using \| as separator
	_bazel__complete_pattern() {
	local workspace=$1 displacement=$2 current=$3 types=$4
	for type in $(echo $types \| tr "\|" "\n"); do
	case "$type" in
	label*)
	_bazel__expand_target_pattern "$workspace" "$displacement" \
	"$current" "$type"
	;;
	info-key)
	compgen -S " " -W "${BAZEL_INFO_KEYS}" -- "$current"
	;;
	"command")
	local commands=$(echo "${BAZEL_COMMAND_LIST}" \
	\| tr " " "\n" \| "grep" -v "^${BAZEL_IGNORED_COMMAND_REGEX}$")
	compgen -S " " -W "${commands}" -- "$current"
	;;
	path)
	compgen -f -- "$current"
	;;
	*)
	compgen -S " " -W "$type" -- "$current"
	;;
	esac
	done
	}

	# Usage: _bazel__expand_options <workspace> <displacement> <current-word>
	# <options>
	#
	# Expands options, making sure that if current-word contains an equals sign,
	# it is handled appropriately.
	_bazel__expand_options() {
	local workspace="$1" displacement="$2" cur="$3" options="$4"
	if [[ $cur =~ = ]]; then
	# also expands special labels
	current=$(echo "$cur" \| cut -f2 -d=)
	_bazel__complete_pattern "$workspace" "$displacement" "$current" \
	"$(compgen -W "$options" -- "$cur" \| cut -f2 -d=)" \
	\| sort -u
	else
	compgen -W "$(echo "$options" \| sed 's\|=.*$\|=\|')" -- "$cur" \
	\| sed 's\|\([^=]\)$\|\1 \|'
	fi
	}


	_bazel__complete_stdout() {
	local cur=$(_bazel__get_cword) word command displacement workspace

	# Determine command: "" (startup-options) or one of $BAZEL_COMMAND_LIST.
	command="$(_bazel__get_command)"

	workspace="$(_bazel__get_workspace_path)"
	displacement="$(_bazel__get_displacement ${workspace})"

	case "$command" in
	"") # Expand startup-options or commands
	local commands=$(echo "${BAZEL_COMMAND_LIST}" \
	\| tr " " "\n" \| "grep" -v "^${BAZEL_IGNORED_COMMAND_REGEX}$")
	_bazel__expand_options "$workspace" "$displacement" "$cur" \
	"${commands}\
	${BAZEL_STARTUP_OPTIONS}"
	;;

	*)
	case "$cur" in
	-*) # Expand options:
	_bazel__expand_options "$workspace" "$displacement" "$cur" \
	"$(_bazel__options_for $command)"
	;;
	*) # Expand target pattern
	expansion_pattern="$(_bazel__expansion_for $command)"
	NON_QUOTE_REGEX="^[\"']"
	if [[ $command = query && $cur =~ $NON_QUOTE_REGEX ]]; then
	: # Ideally we would expand query expressions---it's not
	# that hard, conceptually---but readline is just too
	# damn complex when it comes to quotation. Instead,
	# for query, we just expand target patterns, unless
	# the first char is a quote.
	elif [ -n "$expansion_pattern" ]; then
	_bazel__complete_pattern \
	"$workspace" "$displacement" "$cur" "$expansion_pattern"
	fi
	;;
	esac
	;;
	esac
	}

	_bazel__to_compreply() {
	local replies="$1"
	COMPREPLY=()
	# Trick to preserve whitespaces
	while IFS="" read -r reply; do
	COMPREPLY+=("${reply}")
	done < <(echo "${replies}")
	}

	_bazel__complete() {
	_bazel__to_compreply "$(_bazel__complete_stdout)"
	}

	# Some users have aliases such as bt="bazel test" or bb="bazel build", this
	# completion function allows them to have auto-completion for these aliases.
	_bazel__complete_target_stdout() {
	local cur=$(_bazel__get_cword) word command displacement workspace

	# Determine command: "" (startup-options) or one of $BAZEL_COMMAND_LIST.
	command="$1"

	workspace="$(_bazel__get_workspace_path)"
	displacement="$(_bazel__get_displacement ${workspace})"

	_bazel__to_compreply "$(_bazel__expand_target_pattern "$workspace" "$displacement" \
	"$cur" "$(_bazel__expansion_for $command)")"
	}

	# default completion for bazel
	complete -F _bazel__complete -o nospace "${BAZEL}"
	complete -F _bazel__complete -o nospace "${IBAZEL}"