blob: 6579b643e023554b0e9c3122a1edd54bf461245a [file] [log] [blame]
#!/usr/bin/env bash
# Copyright 2015 The Chromium 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
# `flutter.bat` script in the same directory to ensure that Flutter continues
# to work across all platforms!
# -------------------------------------------------------------------------- #
set -e
unset CDPATH
function follow_links() {
cd -P "${1%/*}"
local file="$PWD/${1##*/}"
while [[ -h "$file" ]]; do
# On Mac OS, readlink -f doesn't work.
cd -P "${file%/*}"
file="$(readlink "$file")"
cd -P "${file%/*}"
echo "$PWD/${file##*/}"
# Convert a filesystem path to a format usable by Dart's URI parser.
function path_uri() {
# Reduce multiple leading slashes to a single slash.
echo "$1" | sed -E -e "s,^/+,/,"
function _rmlock () {
function retry_upgrade {
local total_tries="10"
local remaining_tries=$((total_tries - 1))
while [[ "$remaining_tries" -gt 0 ]]; do
(cd "$FLUTTER_TOOLS_DIR" && "$PUB" upgrade "$VERBOSITY") && break
echo "Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... ($remaining_tries tries left)"
remaining_tries=$((remaining_tries - 1))
sleep 5
if [[ "$remaining_tries" == 0 ]]; then
echo "Command 'pub upgrade' still failed after $total_tries tries, giving up."
return 1
return 0
function upgrade_flutter () {
mkdir -p "$FLUTTER_ROOT/bin/cache"
# This function is executed with a redirect that pipes the source of
# this script into file descriptor 3.
# 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 Mac.
# There is not a direct equivalent, so on platforms that don't have flock,
# we fall back to using a lockfile and spinlock with "shlock". This
# doesn't work as well over NFS as it relies on PIDs. Any platform
# without either of these tools has no locking at all. To determine if we
# have "flock" or "shlock" available, we abuse the "hash" shell built-in.
# The second complication is NFS. On NFS, to obtain an exclusive
# lock you need a file descriptor that is open for writing, because
# NFS implements exclusive locks by writing, or some such. Thus, we
# ignore errors from flock. We do so by using the '|| true' trick,
# since we are running in a 'set -e' environment wherein all errors
# are fatal, and 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.
# For "flock", the lock is released when the file descriptor goes out of
# scope, i.e. when this function returns. The lock is released via
# a trap when using "shlock".
if hash flock 2>/dev/null; then
flock 3 2>/dev/null || true
elif hash shlock 2>/dev/null; then
while ! shlock -f "$FLUTTER_UPGRADE_LOCK" -p $$ ; do sleep .1 ; done
trap _rmlock EXIT
local revision="$(cd "$FLUTTER_ROOT"; git rev-parse HEAD)"
# Invalidate cache if:
# * SNAPSHOT_PATH is not a file, or
# * STAMP_PATH is not a file with nonzero size, or
# * Contents of STAMP_PATH is not our local git HEAD revision, or
# * pubspec.yaml last modified after pubspec.lock
if [[ ! -f "$SNAPSHOT_PATH" || ! -s "$STAMP_PATH" || "$(cat "$STAMP_PATH")" != "$revision" || "$FLUTTER_TOOLS_DIR/pubspec.yaml" -nt "$FLUTTER_TOOLS_DIR/pubspec.lock" ]]; then
rm -f "$FLUTTER_ROOT/version"
touch "$FLUTTER_ROOT/bin/cache/.dartignore"
echo Building flutter tool...
if [[ "$CI" == "true" || "$BOT" == "true" || "$CONTINUOUS_INTEGRATION" == "true" || "$CHROME_HEADLESS" == "1" ]]; then
export PUB_ENVIRONMENT="$PUB_ENVIRONMENT:flutter_install"
if [[ -d "$FLUTTER_ROOT/.pub-cache" ]]; then
export PUB_CACHE="${PUB_CACHE:-"$FLUTTER_ROOT/.pub-cache"}"
echo "$revision" > "$STAMP_PATH"
# The exit here is duplicitous 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 lockfile created by shlock
# is cleaned up.
exit $?
PROG_NAME="$(path_uri "$(follow_links "$BASH_SOURCE")")"
BIN_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
export FLUTTER_ROOT="$(cd "${BIN_DIR}/.." ; pwd -P)"
# Test if running as superuser – but don't warn if running within Docker
if [[ "$EUID" == "0" && ! -f /.dockerenv ]]; then
echo " Woah! You appear to be trying to run flutter as root."
echo " We strongly recommend running the flutter tool without superuser privileges."
echo " /"
echo "📎"
# Test if Git is available on the Host
if ! hash git 2>/dev/null; then
echo "Error: Unable to find git in your PATH."
exit 1
# Test if the flutter directory is a git clone (otherwise git rev-parse HEAD would fail)
if [[ ! -e "$FLUTTER_ROOT/.git" ]]; then
echo "Error: The Flutter directory is not a clone of the GitHub project."
echo " The flutter tool requires Git in order to operate properly;"
echo " to set up Flutter, run the following command:"
echo " git clone -b stable"
exit 1
# To debug the tool, you can uncomment the following lines to enable checked mode and set an observatory port:
(upgrade_flutter) 3< "$PROG_NAME"
# FLUTTER_TOOL_ARGS isn't quoted below, because it is meant to be considered as
# separate space-separated args.