[vm/kernel/aot] Exclude vmservice_io from "product" AOT snapshots.

The `@pragma` annotation on `vmservice_io.main` is modified to only mark it as a
root on non-product builds. Since the annotation is evaluated in the constant
transformation, we need to thread a flag through `gen_kernel.dart` indicating
whether the Kernel produced should target a product precompiler.

# Test Plan

Tested locally on Flutter. Unfortunately it's not possible to test the scenario where
`vmservice_io` is not included, since we don't have any "product" bots. Soon the
flag will be introduced into Flutter, and we will have some coverage from there.

Change-Id: I39f12343038fa221aafe5a55241bff4b8d14ec19
Reviewed-on: https://dart-review.googlesource.com/57501
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>

pkg/vm/bin/gen_kernel.dart

@@ -15,7 +15,7 @@ import 'package:kernel/text/ast_to_text.dart'
     show globalDebuggingNames, NameSystem;
 import 'package:vm/bytecode/gen_bytecode.dart' show isKernelBytecodeEnabled;
 import 'package:vm/kernel_front_end.dart'
-    show compileToKernel, ErrorDetector, ErrorPrinter;
+    show compileToKernel, ErrorDetector, ErrorPrinter, parseCommandLineDefines;
 
 final ArgParser _argParser = new ArgParser(allowTrailingOptions: true)
   ..addOption('platform',
@@ -93,7 +93,7 @@ Future<int> compile(List<String> arguments) async {
   final bool enableConstantEvaluation = options['enable-constant-evaluation'];
   final Map<String, String> environmentDefines = {};
 
-  if (!_parseDefines(options['define'], environmentDefines)) {
+  if (!parseCommandLineDefines(options['define'], environmentDefines, _usage)) {
     return _badUsageExitCode;
   }
 
@@ -179,22 +179,3 @@ Future runBatchModeCompiler() async {
     }
   });
 }
-
-bool _parseDefines(
-    List<String> dFlags, Map<String, String> environmentDefines) {
-  for (final String dflag in dFlags) {
-    final equalsSignIndex = dflag.indexOf('=');
-    if (equalsSignIndex < 0) {
-      environmentDefines[dflag] = '';
-    } else if (equalsSignIndex > 0) {
-      final key = dflag.substring(0, equalsSignIndex);
-      final value = dflag.substring(equalsSignIndex + 1);
-      environmentDefines[key] = value;
-    } else {
-      print('The environment constant options must have a key (was: "$dflag")');
-      print(_usage);
-      return false;
-    }
-  }
-  return true;
-}

pkg/vm/lib/frontend_server.dart

@@ -29,7 +29,8 @@ import 'package:kernel/target/targets.dart';
 import 'package:path/path.dart' as path;
 import 'package:usage/uuid/uuid.dart';
 import 'package:vm/incremental_compiler.dart' show IncrementalCompiler;
-import 'package:vm/kernel_front_end.dart' show compileToKernel;
+import 'package:vm/kernel_front_end.dart'
+    show compileToKernel, parseCommandLineDefines;
 
 ArgParser argParser = new ArgParser(allowTrailingOptions: true)
   ..addFlag('train',
@@ -92,7 +93,10 @@ ArgParser argParser = new ArgParser(allowTrailingOptions: true)
       help: 'Normally the output dill is used to specify which dill to '
           'initialize from, but it can be overwritten here.',
       defaultsTo: null,
-      hide: true);
+      hide: true)
+  ..addMultiOption('define',
+      abbr: 'D',
+      help: 'The values for the environment constants (e.g. -Dkey=value).');
 
 String usage = '''
 Usage: server [options] [input.dart]
@@ -292,6 +296,12 @@ class FrontendCompiler implements CompilerInterface {
       }
     }
 
+    final Map<String, String> environmentDefines = {};
+    if (!parseCommandLineDefines(
+        options['define'], environmentDefines, usage)) {
+      return false;
+    }
+
     final TargetFlags targetFlags = new TargetFlags(
         strongMode: options['strong'], syncAsync: options['sync-async']);
     compilerOptions.target = getTarget(options['target'], targetFlags);
@@ -322,7 +332,8 @@ class FrontendCompiler implements CompilerInterface {
           _mainSource, compilerOptions,
           aot: options['aot'],
           useGlobalTypeFlowAnalysis: options['tfa'],
-          entryPoints: options['entry-points']));
+          entryPoints: options['entry-points'],
+          environmentDefines: environmentDefines));
     }
     if (component != null) {
       if (transformer != null) {

pkg/vm/lib/kernel_front_end.dart

@@ -330,3 +330,22 @@ class ForwardConstantEvaluationErrors implements constants.ErrorReporter {
     return node == null ? TreeNode.noOffset : node.fileOffset;
   }
 }
+
+bool parseCommandLineDefines(
+    List<String> dFlags, Map<String, String> environmentDefines, String usage) {
+  for (final String dflag in dFlags) {
+    final equalsSignIndex = dflag.indexOf('=');
+    if (equalsSignIndex < 0) {
+      environmentDefines[dflag] = '';
+    } else if (equalsSignIndex > 0) {
+      final key = dflag.substring(0, equalsSignIndex);
+      final value = dflag.substring(equalsSignIndex + 1);
+      environmentDefines[key] = value;
+    } else {
+      print('The environment constant options must have a key (was: "$dflag")');
+      print(usage);
+      return false;
+    }
+  }
+  return true;
+}

runtime/bin/main.cc

@@ -37,6 +37,8 @@
 #include "bin/gzip.h"
 #endif
 
+#include "vm/flags.h"
+
 extern "C" {
 extern const uint8_t kDartVmSnapshotData[];
 extern const uint8_t kDartVmSnapshotInstructions[];
@@ -291,10 +293,12 @@ static Dart_Isolate IsolateSetupHelper(Dart_Isolate isolate,
   result = DartUtils::PrepareForScriptLoading(false, Options::trace_loading());
   CHECK_RESULT(result);
 
-  // Set up the load port provided by the service isolate so that we can
-  // load scripts.
-  result = DartUtils::SetupServiceLoadPort();
-  CHECK_RESULT(result);
+  if (FLAG_support_service || !kDartPrecompiledRuntime) {
+    // Set up the load port provided by the service isolate so that we can
+    // load scripts.
+    result = DartUtils::SetupServiceLoadPort();
+    CHECK_RESULT(result);
+  }
 
   // Setup package root if specified.
   result = DartUtils::SetupPackageRoot(package_root, packages_config);

runtime/bin/vmservice/vmservice_io.dart

@@ -220,7 +220,7 @@ _registerSignalHandler() {
   _signalSubscription = _signalWatch(ProcessSignal.SIGQUIT).listen(_onSignal);
 }
 
-@pragma("vm.entry_point")
+@pragma("vm.entry_point", !const bool.fromEnvironment("dart.vm.product"))
 main() {
   // Set embedder hooks.
   VMServiceEmbedderHooks.cleanup = cleanupCallback;

runtime/vm/compiler/aot/precompiler.cc

@@ -342,7 +342,6 @@ void Precompiler::DoCompileAll(
       I->object_store()->set_future_class(null_class);
       I->object_store()->set_pragma_class(null_class);
       I->object_store()->set_completer_class(null_class);
-      I->object_store()->set_stream_iterator_class(null_class);
       I->object_store()->set_symbol_class(null_class);
       I->object_store()->set_compiletime_error_class(null_class);
       I->object_store()->set_simple_instance_of_function(null_function);

runtime/vm/dart.cc

@@ -307,15 +307,11 @@ char* Dart::InitOnce(const uint8_t* vm_isolate_snapshot,
     Service::SetGetServiceAssetsCallback(get_service_assets);
   }
 
-#if defined(DART_PRECOMPILED_RUNTIME)
-  const bool is_precompiled_runtime = true;
-#else
-  const bool is_precompiled_runtime = false;
-#endif
-
   const bool is_dart2_aot_precompiler =
-      FLAG_strong && FLAG_precompiled_mode && !is_precompiled_runtime;
-  if (!is_dart2_aot_precompiler) {
+      FLAG_strong && FLAG_precompiled_mode && !kDartPrecompiledRuntime;
+
+  if (!is_dart2_aot_precompiler &&
+      (FLAG_support_service || !kDartPrecompiledRuntime)) {
     ServiceIsolate::Run();
   }
 

runtime/vm/flag_list.h

@@ -26,6 +26,12 @@
 #define USING_PRODUCT false
 #endif
 
+#if defined(DART_PRECOMPILED_RUNTIME)
+constexpr bool kDartPrecompiledRuntime = true;
+#else
+constexpr bool kDartPrecompiledRuntime = false;
+#endif
+
 // List of all flags in the VM.
 // Flags can be one of three categories:
 // * P roduct flags: Can be set in any of the deployment modes, including in

runtime/vm/object_store.cc

@@ -149,9 +149,6 @@ void ObjectStore::InitKnownObjects() {
   cls = async_lib.LookupClass(Symbols::Completer());
   ASSERT(!cls.IsNull());
   set_completer_class(cls);
-  cls = async_lib.LookupClass(Symbols::StreamIterator());
-  ASSERT(!cls.IsNull());
-  set_stream_iterator_class(cls);
 
   String& function_name = String::Handle(zone);
   Function& function = Function::Handle(zone);

runtime/vm/object_store.h

@@ -58,7 +58,6 @@ class ObjectPointerVisitor;
   RW(Class, pragma_class)                                                      \
   RW(Class, future_class)                                                      \
   RW(Class, completer_class)                                                   \
-  RW(Class, stream_iterator_class)                                             \
   RW(Class, symbol_class)                                                      \
   RW(Class, one_byte_string_class)                                             \
   RW(Class, two_byte_string_class)                                             \

runtime/vm/parser.cc

@@ -9290,7 +9290,7 @@ AstNode* Parser::ParseAwaitForStatement(String* label_name) {
   // Build creation of implicit StreamIterator.
   // var :for-in-iter = new StreamIterator(stream_expr).
   const Class& stream_iterator_cls =
-      Class::ZoneHandle(Z, I->object_store()->stream_iterator_class());
+      Class::ZoneHandle(Z, async_lib.LookupClass(Symbols::StreamIterator()));
   ASSERT(!stream_iterator_cls.IsNull());
   const Function& iterator_ctor = Function::ZoneHandle(
       Z,

sdk/lib/core/annotations.dart

@@ -248,6 +248,7 @@ const Object proxy = const _Proxy();
  * function foo is annotated with a pragma 'other-pragma' specific to OtherTool.
  *
  */
+@pragma('vm.entry_point')
 class pragma {
   /**
    * The name of the hint.