[dart2js, ddc] Remove PRINT_LEGACY_STARS.

Bug: #60327
Change-Id: I32a9f078e4c2ae5fc3b79b4f549a4357a08818d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416043
Reviewed-by: Stephen Adams <sra@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>

pkg/compiler/lib/src/commandline_options.dart

@@ -99,7 +99,6 @@ class Flags {
   static const String noOmitLateNames = '--no-omit-late-names';
 
   static const String preserveUris = '--preserve-uris';
-  static const String printLegacyStars = '--debug-print-legacy-stars';
   static const String showPackageWarnings = '--show-package-warnings';
   static const String suppressHints = '--suppress-hints';
   static const String suppressWarnings = '--suppress-warnings';

pkg/compiler/lib/src/dart2js.dart

@@ -450,7 +450,6 @@ Future<api.CompilationResult> compile(
     _OneOption(Flags.omitLateNames, passThrough),
     _OneOption(Flags.noOmitLateNames, passThrough),
     _OneOption(Flags.preserveUris, ignoreOption),
-    _OneOption(Flags.printLegacyStars, passThrough),
     _OneOption('--force-strip=.*', setStrip),
     _OneOption(Flags.disableDiagnosticColors, (_) {
       enableColors = false;

pkg/compiler/lib/src/kernel/transformations/global/js_get_flag_lowering.dart

@@ -59,7 +59,6 @@ class JsGetFlagLowering {
       _options.features.useContentSecurityPolicy.isEnabled,
     'VARIANCE' => _options.enableVariance,
     'LEGACY' => _options.useLegacySubtyping,
-    'PRINT_LEGACY_STARS' => _options.printLegacyStars,
     _ => null,
   };
 

pkg/compiler/lib/src/options.dart

@@ -552,9 +552,6 @@ class CompilerOptions implements DiagnosticOptions {
   /// Location of the kernel platform `.dill` files.
   Uri? platformBinaries;
 
-  /// Whether to print legacy types as T* rather than T.
-  bool printLegacyStars = false;
-
   /// URI where the compiler should generate the output source map file.
   Uri? sourceMapUri;
 
@@ -934,7 +931,6 @@ class CompilerOptions implements DiagnosticOptions {
       ..generateSourceMap = !_hasOption(options, Flags.noSourceMaps)
       .._outputUri = _extractUriOption(options, '--out=')
       ..platformBinaries = platformBinaries
-      ..printLegacyStars = _hasOption(options, Flags.printLegacyStars)
       ..sourceMapUri = _extractUriOption(options, '--source-map=')
       ..omitImplicitChecks = _hasOption(options, Flags.omitImplicitChecks)
       ..omitAsCasts = _hasOption(options, Flags.omitAsCasts)

pkg/dev_compiler/lib/src/kernel/compiler.dart

@@ -6152,9 +6152,8 @@ class ProgramCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
           var value = flag.value;
           return switch (value) {
             'DEV_COMPILER' => js.boolean(true),
-            // TODO(nshahan): Delete 'PRINT_LEGACY_STARS' and 'LEGACY' after
-            // uses are deleted from dart:_rti.
-            'PRINT_LEGACY_STARS' => js.boolean(false),
+            // TODO(nshahan): Delete 'LEGACY' after uses are deleted from
+            // dart:_rti.
             'LEGACY' => js.boolean(false),
             'MINIFIED' => js.boolean(false),
             'VARIANCE' =>

pkg/dev_compiler/lib/src/kernel/compiler_new.dart

@@ -6600,9 +6600,8 @@ class LibraryCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
           var value = flag.value;
           return switch (value) {
             'DEV_COMPILER' => js.boolean(true),
-            // TODO(nshahan): Delete 'PRINT_LEGACY_STARS' and 'LEGACY' after
-            // uses are deleted from dart:_rti.
-            'PRINT_LEGACY_STARS' => js.boolean(false),
+            // TODO(nshahan): Delete 'LEGACY' after uses are deleted from
+            // dart:_rti.
             'LEGACY' => js.boolean(false),
             'MINIFIED' => js.boolean(false),
             'VARIANCE' =>

sdk/lib/_internal/js_shared/lib/rti.dart

@@ -410,9 +410,6 @@ class Rti {
 // TODO(nshahan): Make private and change the argument type to rti once this
 // method is no longer called from outside the library.
 Rti getLegacyErasedRti(Object? rti) {
-  // When preserving the legacy stars in the runtime type no legacy erasure
-  // happens so the cached version cannot be used.
-  assert(!JS_GET_FLAG('PRINT_LEGACY_STARS'));
   var originalType = _Utils.asRti(rti);
   return Rti._getCachedRuntimeType(originalType)?._rti ??
       _createAndCacheRuntimeType(originalType)._rti;
@@ -1181,9 +1178,6 @@ _Type _createAndCacheRuntimeType(Rti rti) {
 }
 
 _Type _createRuntimeType(Rti rti) {
-  if (JS_GET_FLAG('PRINT_LEGACY_STARS')) {
-    return _Type(rti);
-  }
   String recipe = Rti._getCanonicalRecipe(rti);
   String starErasedRecipe = Rti.getLegacyErasedRecipe(rti);
   if (starErasedRecipe == recipe) {
@@ -1996,16 +1990,7 @@ String _rtiToString(Rti rti, List<String>? genericContext) {
   if (kind == Rti.kindStar) {
     Rti starArgument = Rti._getStarArgument(rti);
     String s = _rtiToString(starArgument, genericContext);
-    if (JS_GET_FLAG('PRINT_LEGACY_STARS')) {
-      int argumentKind = Rti._getKind(starArgument);
-      if (argumentKind == Rti.kindFunction ||
-          argumentKind == Rti.kindGenericFunction) {
-        s = '(' + s + ')';
-      }
-      return s + '*';
-    } else {
-      return s;
-    }
+    return s;
   }
 
   if (kind == Rti.kindQuestion) {