| @ECHO off | 
 | REM Copyright 2017 The Chromium Authors. All rights reserved. | 
 | REM Use of this source code is governed by a BSD-style license that can be | 
 | REM found in the LICENSE file. | 
 |  | 
 |  | 
 | REM ---------------------------------- NOTE ---------------------------------- | 
 | REM | 
 | REM Please keep the logic in this file consistent with the logic in the | 
 | REM `flutter` script in the same directory to ensure that Flutter continues to | 
 | REM work across all platforms! | 
 | REM | 
 | REM -------------------------------------------------------------------------- | 
 |  | 
 | SETLOCAL ENABLEDELAYEDEXPANSION | 
 |  | 
 | FOR %%i IN ("%~dp0..") DO SET FLUTTER_ROOT=%%~fi | 
 |  | 
 | SET flutter_tools_dir=%FLUTTER_ROOT%\packages\flutter_tools | 
 | SET cache_dir=%FLUTTER_ROOT%\bin\cache | 
 | SET snapshot_path=%cache_dir%\flutter_tools.snapshot | 
 | SET stamp_path=%cache_dir%\flutter_tools.stamp | 
 | SET script_path=%flutter_tools_dir%\bin\flutter_tools.dart | 
 | SET dart_sdk_path=%cache_dir%\dart-sdk | 
 | SET dart_stamp_path=%cache_dir%\dart-sdk.stamp | 
 | SET dart_version_path=%FLUTTER_ROOT%\bin\internal\dart-sdk.version | 
 |  | 
 | SET dart=%dart_sdk_path%\bin\dart.exe | 
 | SET pub=%dart_sdk_path%\bin\pub.bat | 
 |  | 
 | REM Test if Git is available on the Host | 
 | where /q git || ECHO Error: Unable to find git in your PATH. && EXIT /B 1 | 
 | REM  Test if the flutter directory is a git clone, otherwise git rev-parse HEAD would fail | 
 | IF NOT EXIST "%flutter_root%\.git" ( | 
 |   ECHO Error: The Flutter directory is not a clone of the GitHub project. | 
 |   EXIT /B 1 | 
 | ) | 
 |  | 
 | REM Ensure that bin/cache exists. | 
 | IF NOT EXIST "%cache_dir%" MKDIR "%cache_dir%" | 
 |  | 
 | REM To debug the tool, you can uncomment the following line to enable checked mode and set an observatory port: | 
 | REM SET FLUTTER_TOOL_ARGS="--observe=65432 --checked" | 
 |  | 
 | :acquire_lock | 
 | 2>NUL ( | 
 |   REM "3" is now stderr because of "2>NUL". | 
 |   CALL :subroutine %* 2>&3 9> "%cache_dir%\flutter.bat.lock" || GOTO acquire_lock | 
 | ) | 
 | GOTO :after_subroutine | 
 |  | 
 | :subroutine | 
 |   PUSHD "%flutter_root%" | 
 |   FOR /f %%r IN ('git rev-parse HEAD') DO SET revision=%%r | 
 |   POPD | 
 |  | 
 |   REM The following IF conditions are all linked with a logical OR. However, | 
 |   REM there is no OR operator in batch and a GOTO construct is used as replacement. | 
 |  | 
 |   IF NOT EXIST "%dart_stamp_path%" GOTO do_sdk_update_and_snapshot | 
 |   SET /P dart_required_version=<"%dart_version_path%" | 
 |   SET /P dart_installed_version=<"%dart_stamp_path%" | 
 |   IF !dart_required_version! NEQ !dart_installed_version! GOTO do_sdk_update_and_snapshot | 
 |   IF NOT EXIST "%snapshot_path%" GOTO do_snapshot | 
 |   IF NOT EXIST "%stamp_path%" GOTO do_snapshot | 
 |   SET /p stamp_value=<"%stamp_path%" | 
 |   IF !stamp_value! NEQ !revision! GOTO do_snapshot | 
 |   REM Compare "last modified" timestamps | 
 |   SET pubspec_yaml_path=%flutter_tools_dir%\pubspec.yaml | 
 |   SET pubspec_lock_path=%flutter_tools_dir%\pubspec.lock | 
 |   FOR %%i IN ("%pubspec_yaml_path%") DO SET yaml_timestamp=%%~ti | 
 |   FOR %%i IN ("%pubspec_lock_path%") DO SET lock_timestamp=%%~ti | 
 |   IF !yaml_timestamp! EQU !lock_timestamp! GOTO do_snapshot | 
 |   FOR /F %%i IN ('DIR /B /O:D "%pubspec_yaml_path%" "%pubspec_lock_path%"') DO SET newer_file=%%i | 
 |   IF "%newer_file%" EQU "pubspec.yaml" GOTO do_snapshot | 
 |  | 
 |   REM Everything is uptodate - exit subroutine | 
 |   EXIT /B | 
 |  | 
 |   :do_sdk_update_and_snapshot | 
 |     ECHO Checking Dart SDK version... | 
 |     CALL PowerShell.exe -ExecutionPolicy Bypass -Command "& '%FLUTTER_ROOT%/bin/internal/update_dart_sdk.ps1'" | 
 |     SET exit_code=%ERRORLEVEL% | 
 |     IF %exit_code% NEQ 0 ( | 
 |       ECHO Error: Unable to update Dart SDK. Retrying... Press Ctrl+C to abort. | 
 |       GOTO :do_sdk_update_and_snapshot | 
 |     ) | 
 |  | 
 |   :do_snapshot | 
 |     ECHO: > "%cache_dir%\.dartignore" | 
 |     ECHO Updating flutter tool... | 
 |     PUSHD "%flutter_tools_dir%" | 
 |     CALL "%pub%" upgrade --verbosity=error --no-packages-dir | 
 |     POPD | 
 |     CALL "%dart%" --snapshot="%snapshot_path%" --packages="%flutter_tools_dir%\.packages" "%script_path%" | 
 |     >"%stamp_path%" ECHO %revision% | 
 |  | 
 |   REM Exit Subroutine | 
 |   EXIT /B | 
 |  | 
 | :after_subroutine | 
 |  | 
 | CALL "%dart%" %FLUTTER_TOOL_ARGS% "%snapshot_path%" %* | 
 | SET exit_code=%ERRORLEVEL% | 
 |  | 
 | REM The VM exits with code 253 if the snapshot version is out-of-date. | 
 | IF /I "%exit_code%" EQU "253" ( | 
 |   CALL "%dart%" --snapshot="%snapshot_path%" --packages="%flutter_tools_dir%\.packages" "%script_path%" | 
 |   CALL "%dart%" %FLUTTER_TOOL_ARGS% "%snapshot_path%" %* | 
 |   SET exit_code=%ERRORLEVEL% | 
 | ) | 
 |  | 
 | EXIT /B %exit_code% |