bin/internal/shared.sh - mirrors/flutter - Git at Google

 #!/usr/bin/env bash
 # Copyright 2014 The Flutter Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.


 # ---------------------------------- NOTE ---------------------------------- #
 #
 # Please keep the logic in this file consistent with the logic in the
 # `shared.bat` script in the same directory to ensure that Flutter & Dart continue
 # to work across all platforms!
 #
 # -------------------------------------------------------------------------- #

 set -e

 # Needed because if it is set, cd may print the path it changed to.
 unset CDPATH

 function pub_upgrade_with_retry {
   local total_tries="10"
   local remaining_tries=$((total_tries - 1))
   while [[ "$remaining_tries" -gt 0 ]]; do
     (cd "$FLUTTER_TOOLS_DIR" && "$DART" __deprecated_pub upgrade "$VERBOSITY" --no-precompile) && break
     >&2 echo "Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... ($remaining_tries tries left)"
     remaining_tries=$((remaining_tries - 1))
     sleep 5
   done

   if [[ "$remaining_tries" == 0 ]]; then
     >&2 echo "Command 'pub upgrade' still failed after $total_tries tries, giving up."
     return 1
   fi
   return 0
 }

 # Trap function for removing any remaining lock file at exit.
 function _rmlock () {
   [ -n "$FLUTTER_UPGRADE_LOCK" ] && rm -rf "$FLUTTER_UPGRADE_LOCK"
 }

 # Determines which lock method to use, based on what is available on the system.
 # Returns a non-zero value if the lock was not acquired, zero if acquired.
 function _lock () {
   if hash flock 2>/dev/null; then
     flock --nonblock --exclusive 7 2>/dev/null
   elif hash shlock 2>/dev/null; then
     shlock -f "$1" -p $$
   else
     mkdir "$1" 2>/dev/null
   fi
 }

 # Waits for an update lock to be acquired.
 #
 # To ensure that we don't simultaneously update Dart in multiple parallel
 # instances, we try to obtain an exclusive lock on this file descriptor (and
 # thus this script's source file) while we are updating Dart and compiling the
 # script. To do this, we try to use the command line program "flock", which is
 # available on many Unix-like platforms, in particular on most Linux
 # distributions. You give it a file descriptor, and it locks the corresponding
 # file, having inherited the file descriptor from the shell.
 #
 # Complicating matters, there are two major scenarios where this will not
 # work.
 #
 # The first is if the platform doesn't have "flock", for example on macOS. There
 # is not a direct equivalent, so on platforms that don't have flock, we fall
 # back to using trying to use the shlock command, and if that doesn't exist,
 # then we use mkdir as an atomic operation to create a lock directory. If mkdir
 # is able to create the directory, then the lock is acquired. To determine if we
 # have "flock" or "shlock" available, we use the "hash" shell built-in.
 #
 # The second complication is on network file shares. On NFS, to obtain an
 # exclusive lock you need a file descriptor that is open for writing. Thus, we
 # ignore errors from flock by redirecting all output to /dev/null, since users
 # will typically not care about errors from flock and are more likely to be
 # confused by them than helped. The "shlock" method doesn't work for network
 # shares, since it is PID-based. The "mkdir" method does work over NFS
 # implementations that support atomic directory creation (which is most of
 # them). The "schlock" and "flock" commands are more reliable than the mkdir
 # method, however, or we would use mkdir in all cases.
 #
 # The upgrade_flutter function calling _wait_for_lock is executed in a subshell
 # with a redirect that pipes the source of this script into file descriptor 7.
 # A flock lock is released when this subshell exits and file descriptor 7 is
 # closed. The mkdir lock is released via an exit trap from the subshell that
 # deletes the lock directory.
 function _wait_for_lock () {
   FLUTTER_UPGRADE_LOCK="$FLUTTER_ROOT/bin/cache/.upgrade_lock"
   local waiting_message_displayed
   while ! _lock "$FLUTTER_UPGRADE_LOCK"; do
     if [[ -z $waiting_message_displayed ]]; then
       # Print with a return so that if the Dart code also prints this message
       # when it does its own lock, the message won't appear twice. Be sure that
       # the clearing printf below has the same number of space characters.
       printf "Waiting for another flutter command to release the startup lock...\r" >&2;
       waiting_message_displayed="true"
     fi
     sleep .1;
   done
   if [[ $waiting_message_displayed == "true" ]]; then
     # Clear the waiting message so it doesn't overlap any following text.
     printf "                                                                  \r" >&2;
   fi
   unset waiting_message_displayed
   # If the lock file is acquired, make sure that it is removed on exit.
   trap _rmlock INT TERM EXIT
 }

 # This function is always run in a subshell. Running the function in a subshell
 # is required to make sure any lock directory is cleaned up by the exit trap in
 # _wait_for_lock.
 function upgrade_flutter () (
   mkdir -p "$FLUTTER_ROOT/bin/cache"

   local revision="$(cd "$FLUTTER_ROOT"; git rev-parse HEAD)"
   local compilekey="$revision:$FLUTTER_TOOL_ARGS"

   # Invalidate cache if:
   #  * SNAPSHOT_PATH is not a file, or
   #  * STAMP_PATH is not a file, or
   #  * STAMP_PATH is an empty file, or
   #  * Contents of STAMP_PATH is not what we are going to compile, or
   #  * pubspec.yaml last modified after pubspec.lock
   if [[ ! -f "$SNAPSHOT_PATH" || ! -s "$STAMP_PATH" || "$(cat "$STAMP_PATH")" != "$compilekey" || "$FLUTTER_TOOLS_DIR/pubspec.yaml" -nt "$FLUTTER_TOOLS_DIR/pubspec.lock" ]]; then
     # Waits for the update lock to be acquired. Placing this check inside the
     # conditional allows the majority of flutter/dart installations to bypass
     # the lock entirely, but as a result this required a second verification that
     # the SDK is up to date.
     _wait_for_lock

     # A different shell process might have updated the tool/SDK.
     if [[ -f "$SNAPSHOT_PATH" && -s "$STAMP_PATH" && "$(cat "$STAMP_PATH")" == "$compilekey" && "$FLUTTER_TOOLS_DIR/pubspec.yaml" -ot "$FLUTTER_TOOLS_DIR/pubspec.lock" ]]; then
       exit $?
     fi

     # Fetch Dart...
     rm -f "$FLUTTER_ROOT/version"
     touch "$FLUTTER_ROOT/bin/cache/.dartignore"
     "$FLUTTER_ROOT/bin/internal/update_dart_sdk.sh"

     >&2 echo Building flutter tool...

     # Prepare packages...
     VERBOSITY="--verbosity=error"
     if [[ "$CI" == "true" || "$BOT" == "true" || "$CONTINUOUS_INTEGRATION" == "true" || "$CHROME_HEADLESS" == "1" ]]; then
       PUB_ENVIRONMENT="$PUB_ENVIRONMENT:flutter_bot"
       VERBOSITY="--verbosity=normal"
     fi
     export PUB_ENVIRONMENT="$PUB_ENVIRONMENT:flutter_install"
     if [[ -d "$FLUTTER_ROOT/.pub-cache" ]]; then
       export PUB_CACHE="${PUB_CACHE:-"$FLUTTER_ROOT/.pub-cache"}"
     fi
     pub_upgrade_with_retry

     # Compile...
     "$DART" --verbosity=error --disable-dart-dev $FLUTTER_TOOL_ARGS --snapshot="$SNAPSHOT_PATH" --packages="$FLUTTER_TOOLS_DIR/.dart_tool/package_config.json" --no-enable-mirrors "$SCRIPT_PATH"
     echo "$compilekey" > "$STAMP_PATH"
   fi
   # The exit here is extraneous since the function is run in a subshell, but
   # this serves as documentation that running the function in a subshell is
   # required to make sure any lock directory created by mkdir is cleaned up.
   exit $?
 )

 # This function is intended to be executed by entrypoints (e.g. `//bin/flutter`
 # and `//bin/dart`). PROG_NAME and BIN_DIR should already be set by those
 # entrypoints.
 function shared::execute() {
   export FLUTTER_ROOT="$(cd "${BIN_DIR}/.." ; pwd -P)"

   # If present, run the bootstrap script first
   BOOTSTRAP_PATH="$FLUTTER_ROOT/bin/internal/bootstrap.sh"
   if [ -f "$BOOTSTRAP_PATH" ]; then
     source "$BOOTSTRAP_PATH"
   fi

   FLUTTER_TOOLS_DIR="$FLUTTER_ROOT/packages/flutter_tools"
   SNAPSHOT_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.snapshot"
   STAMP_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.stamp"
   SCRIPT_PATH="$FLUTTER_TOOLS_DIR/bin/flutter_tools.dart"
   DART_SDK_PATH="$FLUTTER_ROOT/bin/cache/dart-sdk"

   DART="$DART_SDK_PATH/bin/dart"

   # If running over git-bash, overrides the default UNIX executables with win32
   # executables
   case "$(uname -s)" in
     MINGW*)
       DART="$DART.exe"
       ;;
   esac

   # Test if running as superuser – but don't warn if running within Docker or CI.
   if [[ "$EUID" == "0" && ! -f /.dockerenv && "$CI" != "true" && "$BOT" != "true" && "$CONTINUOUS_INTEGRATION" != "true" ]]; then
     >&2 echo "   Woah! You appear to be trying to run flutter as root."
     >&2 echo "   We strongly recommend running the flutter tool without superuser privileges."
     >&2 echo "  /"
     >&2 echo "📎"
   fi

   # Test if Git is available on the Host
   if ! hash git 2>/dev/null; then
     >&2 echo "Error: Unable to find git in your PATH."
     exit 1
   fi
   # Test if the flutter directory is a git clone (otherwise git rev-parse HEAD
   # would fail)
   if [[ ! -e "$FLUTTER_ROOT/.git" ]]; then
     >&2 echo "Error: The Flutter directory is not a clone of the GitHub project."
     >&2 echo "       The flutter tool requires Git in order to operate properly;"
     >&2 echo "       to install Flutter, see the instructions at:"
     >&2 echo "       https://flutter.dev/get-started"
     exit 1
   fi

   upgrade_flutter 7< "$PROG_NAME"

   BIN_NAME="$(basename "$PROG_NAME")"
   case "$BIN_NAME" in
     flutter*)
       # FLUTTER_TOOL_ARGS aren't quoted below, because it is meant to be
       # considered as separate space-separated args.
       exec "$DART" --disable-dart-dev --packages="$FLUTTER_TOOLS_DIR/.dart_tool/package_config.json" $FLUTTER_TOOL_ARGS "$SNAPSHOT_PATH" "$@"
       ;;
     dart*)
       exec "$DART" "$@"
       ;;
     *)
       >&2 echo "Error! Executable name $BIN_NAME not recognized!"
       exit 1
       ;;
   esac
 }
	#!/usr/bin/env bash
	# Copyright 2014 The Flutter Authors. All rights reserved.
	# Use of this source code is governed by a BSD-style license that can be
	# found in the LICENSE file.


	# ---------------------------------- NOTE ---------------------------------- #
	#
	# Please keep the logic in this file consistent with the logic in the
	# `shared.bat` script in the same directory to ensure that Flutter & Dart continue
	# to work across all platforms!
	#
	# -------------------------------------------------------------------------- #

	set -e

	# Needed because if it is set, cd may print the path it changed to.
	unset CDPATH

	function pub_upgrade_with_retry {
	local total_tries="10"
	local remaining_tries=$((total_tries - 1))
	while [[ "$remaining_tries" -gt 0 ]]; do
	(cd "$FLUTTER_TOOLS_DIR" && "$DART" __deprecated_pub upgrade "$VERBOSITY" --no-precompile) && break
	>&2 echo "Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... ($remaining_tries tries left)"
	remaining_tries=$((remaining_tries - 1))
	sleep 5
	done

	if [[ "$remaining_tries" == 0 ]]; then
	>&2 echo "Command 'pub upgrade' still failed after $total_tries tries, giving up."
	return 1
	fi
	return 0
	}

	# Trap function for removing any remaining lock file at exit.
	function _rmlock () {
	[ -n "$FLUTTER_UPGRADE_LOCK" ] && rm -rf "$FLUTTER_UPGRADE_LOCK"
	}

	# Determines which lock method to use, based on what is available on the system.
	# Returns a non-zero value if the lock was not acquired, zero if acquired.
	function _lock () {
	if hash flock 2>/dev/null; then
	flock --nonblock --exclusive 7 2>/dev/null
	elif hash shlock 2>/dev/null; then
	shlock -f "$1" -p $$
	else
	mkdir "$1" 2>/dev/null
	fi
	}

	# Waits for an update lock to be acquired.
	#
	# To ensure that we don't simultaneously update Dart in multiple parallel
	# instances, we try to obtain an exclusive lock on this file descriptor (and
	# thus this script's source file) while we are updating Dart and compiling the
	# script. To do this, we try to use the command line program "flock", which is
	# available on many Unix-like platforms, in particular on most Linux
	# distributions. You give it a file descriptor, and it locks the corresponding
	# file, having inherited the file descriptor from the shell.
	#
	# Complicating matters, there are two major scenarios where this will not
	# work.
	#
	# The first is if the platform doesn't have "flock", for example on macOS. There
	# is not a direct equivalent, so on platforms that don't have flock, we fall
	# back to using trying to use the shlock command, and if that doesn't exist,
	# then we use mkdir as an atomic operation to create a lock directory. If mkdir
	# is able to create the directory, then the lock is acquired. To determine if we
	# have "flock" or "shlock" available, we use the "hash" shell built-in.
	#
	# The second complication is on network file shares. On NFS, to obtain an
	# exclusive lock you need a file descriptor that is open for writing. Thus, we
	# ignore errors from flock by redirecting all output to /dev/null, since users
	# will typically not care about errors from flock and are more likely to be
	# confused by them than helped. The "shlock" method doesn't work for network
	# shares, since it is PID-based. The "mkdir" method does work over NFS
	# implementations that support atomic directory creation (which is most of
	# them). The "schlock" and "flock" commands are more reliable than the mkdir
	# method, however, or we would use mkdir in all cases.
	#
	# The upgrade_flutter function calling _wait_for_lock is executed in a subshell
	# with a redirect that pipes the source of this script into file descriptor 7.
	# A flock lock is released when this subshell exits and file descriptor 7 is
	# closed. The mkdir lock is released via an exit trap from the subshell that
	# deletes the lock directory.
	function _wait_for_lock () {
	FLUTTER_UPGRADE_LOCK="$FLUTTER_ROOT/bin/cache/.upgrade_lock"
	local waiting_message_displayed
	while ! _lock "$FLUTTER_UPGRADE_LOCK"; do
	if [[ -z $waiting_message_displayed ]]; then
	# Print with a return so that if the Dart code also prints this message
	# when it does its own lock, the message won't appear twice. Be sure that
	# the clearing printf below has the same number of space characters.
	printf "Waiting for another flutter command to release the startup lock...\r" >&2;
	waiting_message_displayed="true"
	fi
	sleep .1;
	done
	if [[ $waiting_message_displayed == "true" ]]; then
	# Clear the waiting message so it doesn't overlap any following text.
	printf " \r" >&2;
	fi
	unset waiting_message_displayed
	# If the lock file is acquired, make sure that it is removed on exit.
	trap _rmlock INT TERM EXIT
	}

	# This function is always run in a subshell. Running the function in a subshell
	# is required to make sure any lock directory is cleaned up by the exit trap in
	# _wait_for_lock.
	function upgrade_flutter () (
	mkdir -p "$FLUTTER_ROOT/bin/cache"

	local revision="$(cd "$FLUTTER_ROOT"; git rev-parse HEAD)"
	local compilekey="$revision:$FLUTTER_TOOL_ARGS"

	# Invalidate cache if:
	# * SNAPSHOT_PATH is not a file, or
	# * STAMP_PATH is not a file, or
	# * STAMP_PATH is an empty file, or
	# * Contents of STAMP_PATH is not what we are going to compile, or
	# * pubspec.yaml last modified after pubspec.lock
	if [[ ! -f "$SNAPSHOT_PATH" \|\| ! -s "$STAMP_PATH" \|\| "$(cat "$STAMP_PATH")" != "$compilekey" \|\| "$FLUTTER_TOOLS_DIR/pubspec.yaml" -nt "$FLUTTER_TOOLS_DIR/pubspec.lock" ]]; then
	# Waits for the update lock to be acquired. Placing this check inside the
	# conditional allows the majority of flutter/dart installations to bypass
	# the lock entirely, but as a result this required a second verification that
	# the SDK is up to date.
	_wait_for_lock

	# A different shell process might have updated the tool/SDK.
	if [[ -f "$SNAPSHOT_PATH" && -s "$STAMP_PATH" && "$(cat "$STAMP_PATH")" == "$compilekey" && "$FLUTTER_TOOLS_DIR/pubspec.yaml" -ot "$FLUTTER_TOOLS_DIR/pubspec.lock" ]]; then
	exit $?
	fi

	# Fetch Dart...
	rm -f "$FLUTTER_ROOT/version"
	touch "$FLUTTER_ROOT/bin/cache/.dartignore"
	"$FLUTTER_ROOT/bin/internal/update_dart_sdk.sh"

	>&2 echo Building flutter tool...

	# Prepare packages...
	VERBOSITY="--verbosity=error"
	if [[ "$CI" == "true" \|\| "$BOT" == "true" \|\| "$CONTINUOUS_INTEGRATION" == "true" \|\| "$CHROME_HEADLESS" == "1" ]]; then
	PUB_ENVIRONMENT="$PUB_ENVIRONMENT:flutter_bot"
	VERBOSITY="--verbosity=normal"
	fi
	export PUB_ENVIRONMENT="$PUB_ENVIRONMENT:flutter_install"
	if [[ -d "$FLUTTER_ROOT/.pub-cache" ]]; then
	export PUB_CACHE="${PUB_CACHE:-"$FLUTTER_ROOT/.pub-cache"}"
	fi
	pub_upgrade_with_retry

	# Compile...
	"$DART" --verbosity=error --disable-dart-dev $FLUTTER_TOOL_ARGS --snapshot="$SNAPSHOT_PATH" --packages="$FLUTTER_TOOLS_DIR/.dart_tool/package_config.json" --no-enable-mirrors "$SCRIPT_PATH"
	echo "$compilekey" > "$STAMP_PATH"
	fi
	# The exit here is extraneous since the function is run in a subshell, but
	# this serves as documentation that running the function in a subshell is
	# required to make sure any lock directory created by mkdir is cleaned up.
	exit $?
	)

	# This function is intended to be executed by entrypoints (e.g. `//bin/flutter`
	# and `//bin/dart`). PROG_NAME and BIN_DIR should already be set by those
	# entrypoints.
	function shared::execute() {
	export FLUTTER_ROOT="$(cd "${BIN_DIR}/.." ; pwd -P)"

	# If present, run the bootstrap script first
	BOOTSTRAP_PATH="$FLUTTER_ROOT/bin/internal/bootstrap.sh"
	if [ -f "$BOOTSTRAP_PATH" ]; then
	source "$BOOTSTRAP_PATH"
	fi

	FLUTTER_TOOLS_DIR="$FLUTTER_ROOT/packages/flutter_tools"
	SNAPSHOT_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.snapshot"
	STAMP_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.stamp"
	SCRIPT_PATH="$FLUTTER_TOOLS_DIR/bin/flutter_tools.dart"
	DART_SDK_PATH="$FLUTTER_ROOT/bin/cache/dart-sdk"

	DART="$DART_SDK_PATH/bin/dart"

	# If running over git-bash, overrides the default UNIX executables with win32
	# executables
	case "$(uname -s)" in
	MINGW*)
	DART="$DART.exe"
	;;
	esac

	# Test if running as superuser – but don't warn if running within Docker or CI.
	if [[ "$EUID" == "0" && ! -f /.dockerenv && "$CI" != "true" && "$BOT" != "true" && "$CONTINUOUS_INTEGRATION" != "true" ]]; then
	>&2 echo " Woah! You appear to be trying to run flutter as root."
	>&2 echo " We strongly recommend running the flutter tool without superuser privileges."
	>&2 echo " /"
	>&2 echo "📎"
	fi

	# Test if Git is available on the Host
	if ! hash git 2>/dev/null; then
	>&2 echo "Error: Unable to find git in your PATH."
	exit 1
	fi
	# Test if the flutter directory is a git clone (otherwise git rev-parse HEAD
	# would fail)
	if [[ ! -e "$FLUTTER_ROOT/.git" ]]; then
	>&2 echo "Error: The Flutter directory is not a clone of the GitHub project."
	>&2 echo " The flutter tool requires Git in order to operate properly;"
	>&2 echo " to install Flutter, see the instructions at:"
	>&2 echo " https://flutter.dev/get-started"
	exit 1
	fi

	upgrade_flutter 7< "$PROG_NAME"

	BIN_NAME="$(basename "$PROG_NAME")"
	case "$BIN_NAME" in
	flutter*)
	# FLUTTER_TOOL_ARGS aren't quoted below, because it is meant to be
	# considered as separate space-separated args.
	exec "$DART" --disable-dart-dev --packages="$FLUTTER_TOOLS_DIR/.dart_tool/package_config.json" $FLUTTER_TOOL_ARGS "$SNAPSHOT_PATH" "$@"
	;;
	dart*)
	exec "$DART" "$@"
	;;
	*)
	>&2 echo "Error! Executable name $BIN_NAME not recognized!"
	exit 1
	;;
	esac
	}