Friendlier flutter tool messages for dynamic mode (#26378)

packages/flutter_tools/lib/src/build_info.dart

@@ -119,6 +119,7 @@ class BuildInfo {
   bool get supportsEmulator => isEmulatorBuildMode(mode);
   bool get supportsSimulator => isEmulatorBuildMode(mode);
   String get modeName => getModeName(mode);
+  String get friendlyModeName => getFriendlyModeName(mode);
 
   BuildInfo withTargetPlatform(TargetPlatform targetPlatform) =>
       BuildInfo(mode, flavor,
@@ -142,6 +143,10 @@ enum BuildMode {
 
 String getModeName(BuildMode mode) => getEnumName(mode);
 
+String getFriendlyModeName(BuildMode mode) {
+  return snakeCase(getModeName(mode)).replaceAll('_', ' ');
+}
+
 // Returns true if the selected build mode uses ahead-of-time compilation.
 bool isAotBuildMode(BuildMode mode) {
   return mode == BuildMode.profile || mode == BuildMode.release;

packages/flutter_tools/lib/src/bundle.dart

@@ -85,7 +85,7 @@ Future<void> build({
 
     } else if (!fs.file(compilationTraceFilePath).existsSync()) {
       // Be forgiving if compilation trace file is missing.
-      printError('Warning: Ignoring missing compilation training file $compilationTraceFilePath.');
+      printStatus('No compilation trace available. To optimize performance, consider using --train.');
       final File tmp = fs.systemTempDirectory.childFile('flutterEmptyCompilationTrace.txt');
       compilationTraceFilePath = (tmp..createSync(recursive: true)).path;
 

packages/flutter_tools/lib/src/commands/build_aot.dart

@@ -70,7 +70,7 @@ class BuildAotCommand extends BuildSubCommand {
     if (!argResults['quiet']) {
       final String typeName = artifacts.getEngineType(platform, buildMode);
       status = logger.startProgress(
-        'Building AOT snapshot in ${getModeName(getBuildMode())} mode ($typeName)...',
+        'Building AOT snapshot in ${getFriendlyModeName(getBuildMode())} mode ($typeName)...',
         expectSlowOperation: true,
       );
     }

packages/flutter_tools/lib/src/commands/build_ios.dart

@@ -70,7 +70,7 @@ class BuildIOSCommand extends BuildSubCommand {
     }
     final BuildInfo buildInfo = getBuildInfo();
     if (forSimulator && !buildInfo.supportsSimulator)
-      throwToolExit('${toTitleCase(buildInfo.modeName)} mode is not supported for simulators.');
+      throwToolExit('${toTitleCase(buildInfo.friendlyModeName)} mode is not supported for simulators.');
 
     final String logTarget = forSimulator ? 'simulator' : 'device';
 

packages/flutter_tools/lib/src/commands/daemon.dart

@@ -342,7 +342,7 @@ class AppDomain extends Domain {
     String isolateFilter,
   }) async {
     if (await device.isLocalEmulator && !options.buildInfo.supportsEmulator) {
-      throw '${toTitleCase(options.buildInfo.modeName)} mode is not supported for emulators.';
+      throw '${toTitleCase(options.buildInfo.friendlyModeName)} mode is not supported for emulators.';
     }
 
     // We change the current working directory for the duration of the `start` command.

packages/flutter_tools/lib/src/commands/run.dart

@@ -303,7 +303,7 @@ class RunCommand extends RunCommandBase {
         }
 
         if (!isEmulatorBuildMode(getBuildMode())) {
-          throwToolExit('${toTitleCase(getModeName(getBuildMode()))} mode is not supported for emulators.');
+          throwToolExit('${toTitleCase(getFriendlyModeName(getBuildMode()))} mode is not supported for emulators.');
         }
       }
     }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -265,7 +265,7 @@ class FlutterDevice {
     bool shouldBuild,
   }) async {
     final bool prebuiltMode = hotRunner.applicationBinary != null;
-    final String modeName = hotRunner.debuggingOptions.buildInfo.modeName;
+    final String modeName = hotRunner.debuggingOptions.buildInfo.friendlyModeName;
     printStatus('Launching ${getDisplayPath(hotRunner.mainPath)} on ${device.name} in $modeName mode...');
 
     final TargetPlatform targetPlatform = await device.targetPlatform;
@@ -324,7 +324,7 @@ class FlutterDevice {
       applicationBinary: coldRunner.applicationBinary
     );
 
-    final String modeName = coldRunner.debuggingOptions.buildInfo.modeName;
+    final String modeName = coldRunner.debuggingOptions.buildInfo.friendlyModeName;
     final bool prebuiltMode = coldRunner.applicationBinary != null;
     if (coldRunner.mainPath == null) {
       assert(prebuiltMode);