add gclient/ninja build logic

Author: yjbanov

lib/web_ui/dev/felt.bat

@@ -5,6 +5,13 @@
 @ECHO OFF
 SETLOCAL
 
+:: Make sure gclient and ninja exist. Otherwise felt won't work.
+FOR /F "tokens=1-2 delims=:" %%a in ('where gclient') DO SET GCLIENT_PATH=%%b
+IF %GCLIENT_PATH%==[] (ECHO "ERROR: gclient is not in your PATH")
+
+FOR /F "tokens=1-2 delims=:" %%a in ('where ninja') DO SET NINJA_PATH=%%b
+IF %NINJA_PATH%==[] (ECHO "ERROR: ninja is not in your PATH")
+
 :: Starting from this script's path, walk up to engine source directory.
 SET SCRIPT_DIR=%~dp0
 FOR %%a IN ("%SCRIPT_DIR:~0,-1%") DO SET TMP=%%~dpa
@@ -25,9 +32,26 @@ SET FELT_PATH=%DEV_DIR%\felt.dart
 SET DART_TOOL_DIR=%WEB_UI_DIR%\.dart_tool
 SET SNAPSHOT_PATH=%DART_TOOL_DIR%\felt.snapshot
 
-:: Set revision from using git in Flutter directory.
-CD %FLUTTER_DIR%
-FOR /F "tokens=1 delims=:" %%a in ('git rev-parse HEAD') DO SET REVISION=%%a
+SET needsHostDebugUnoptRebuild=0
+for %%x in (%*) do (
+  if ["%%~x"]==["--clean"] (
+    ECHO Clean rebuild requested
+    SET needsHostDebugUnoptRebuild=1
+  )
+)
+
+IF NOT EXIST %OUT_DIR% (SET needsHostDebugUnoptRebuild=1)
+IF NOT EXIST %HOST_DEBUG_UNOPT_DIR% (SET needsHostDebugUnoptRebuild=1)
+
+IF %needsHostDebugUnoptRebuild%==1 (
+  ECHO Building host_debug_unopt
+  :: Delete old snapshot, if any, because the new Dart SDK may invalidate it.
+  IF EXIST "%SNAPSHOT_PATH%" (
+    del %SNAPSHOT_PATH%
+  )
+  CALL gclient sync -D
+  CALL python %GN% --unoptimized --full-dart-sdk
+  CALL ninja -C %HOST_DEBUG_UNOPT_DIR%)
 
 cd %WEB_UI_DIR%
 IF NOT EXIST "%SNAPSHOT_PATH%" (

lib/web_ui/dev/felt.dart

@@ -25,7 +25,10 @@ CommandRunner runner = CommandRunner<bool>(
   ..addCommand(TestCommand())
   ..addCommand(BuildCommand());
 
-void main(List<String> args) async {
+void main(List<String> rawArgs) async {
+  // Remove --clean from the list as that's processed by the wrapper script.
+  final List<String> args = rawArgs.where((arg) => arg != '--clean').toList();
+
   if (args.isEmpty) {
     // The felt tool was invoked with no arguments. Print usage.
     runner.printUsage();