Revert "Introduce IKG into kernel-service to support incremental compilation."

utils/kernel-service/kernel-service.dart

Index: utils/kernel-service/kernel-service.dart
diff --git a/utils/kernel-service/kernel-service.dart b/utils/kernel-service/kernel-service.dart
index cd5ae0ca70a75cb02189cff016fa9163875b6de5..92cb34eb2da696525bf4b9982f17e9839399e0c0 100644
--- a/utils/kernel-service/kernel-service.dart
+++ b/utils/kernel-service/kernel-service.dart
@@ -21,14 +21,12 @@
 library runtime.tools.kernel_service;
 
 import 'dart:async' show Future;
-import 'dart:convert' show JSON;
 import 'dart:io' show Platform hide FileSystemEntity;
 import 'dart:isolate';
 import 'dart:typed_data' show Uint8List;
 
 import 'package:front_end/file_system.dart';
 import 'package:front_end/front_end.dart';
-import 'package:front_end/incremental_kernel_generator.dart';
 import 'package:front_end/memory_file_system.dart';
 import 'package:front_end/physical_file_system.dart';
 import 'package:front_end/src/fasta/kernel/utils.dart';
@@ -40,119 +38,6 @@ import 'package:kernel/target/vm_fasta.dart' show VmFastaTarget;
 const bool verbose = const bool.fromEnvironment('DFE_VERBOSE');
 const bool strongMode = const bool.fromEnvironment('DFE_STRONG_MODE');
 
-abstract class Compiler {
-  final FileSystem fileSystem;
-  final List<String> errors = new List<String>();
-
-  CompilerOptions options;
-
-  Compiler(this.fileSystem) {
-    Uri packagesUri = (Platform.packageConfig != null)
-        ? Uri.parse(Platform.packageConfig)
-        : null;
-
-    Uri sdkSummary = Uri.base
-        .resolveUri(new Uri.file(Platform.resolvedExecutable))
-        .resolveUri(new Uri.directory("patched_sdk"))
-        // TODO(sigmund): use outline.dill when the mixin transformer is
-        // modular.
-        .resolve('platform.dill');
-
-    if (verbose) {
-      print("DFE: Platform.packageConfig: ${Platform.packageConfig}");
-      print("DFE: packagesUri: ${packagesUri}");
-      print("DFE: Platform.resolvedExecutable: ${Platform.resolvedExecutable}");
-      print("DFE: sdkSummary: ${sdkSummary}");
-    }
-
-    options = new CompilerOptions()
-      ..strongMode = strongMode
-      ..fileSystem = fileSystem
-      ..target = new VmFastaTarget(new TargetFlags(strongMode: strongMode))
-      ..packagesFileUri = packagesUri
-      ..sdkSummary = sdkSummary
-      ..verbose = verbose
-      ..throwOnErrors = false
-      ..reportMessages = true
-      ..onError = (CompilationMessage e) {
-        if (e.severity == Severity.error) {
-          // TODO(sigmund): support emitting code with errors as long as they
-          // are handled in the generated code (issue #30194).
-          errors.add(e.message);
-        }
-      };
-  }
-
-  Future<Program> compile(Uri script);
-}
-
-class IncrementalCompiler extends Compiler {
-  IncrementalKernelGenerator generator;
-
-  IncrementalCompiler(FileSystem fileSystem) : super(fileSystem);
-
-  @override
-  Future<Program> compile(Uri script) async {
-    if (generator == null) {
-      generator = await IncrementalKernelGenerator.newInstance(options, script);
-    }
-    DeltaProgram deltaProgram = await generator.computeDelta();
-    // TODO(aam): Accepting/rejecting should be done based on VM response.
-    generator.acceptLastDelta();
-    return deltaProgram.newProgram;
-  }
-
-  void invalidate(Uri uri) {
-    generator.invalidate(uri);
-  }
-}
-
-class SingleShotCompiler extends Compiler {
-  final bool requireMain;
-
-  SingleShotCompiler(FileSystem fileSystem, this.requireMain)
-      : super(fileSystem);
-
-  @override
-  Future<Program> compile(Uri script) async {
-    return requireMain
-        ? kernelForProgram(script, options)
-        : kernelForBuildUnit([script], options..chaseDependencies = true);
-  }
-}
-
-final Map<int, Compiler> isolateCompilers = new Map<int, Compiler>();
-
-Future<Compiler> lookupOrBuildNewIncrementalCompiler(
-    int isolateId, List sourceFiles) async {
-  IncrementalCompiler compiler;
-  if (isolateCompilers.containsKey(isolateId)) {
-    compiler = isolateCompilers[isolateId];
-    final HybridFileSystem fileSystem = compiler.fileSystem;
-    if (sourceFiles != null) {
-      for (int i = 0; i < sourceFiles.length ~/ 2; i++) {
-        Uri uri = Uri.parse(sourceFiles[i * 2]);
-        fileSystem.memory
-            .entityForUri(uri)
-            .writeAsBytesSync(sourceFiles[i * 2 + 1]);
-        compiler.invalidate(uri);
-      }
-    }
-  } else {
-    final FileSystem fileSystem = sourceFiles == null
-        ? PhysicalFileSystem.instance
-        : _buildFileSystem(sourceFiles);
-
-    // TODO(aam): IncrementalCompiler instance created below have to be
-    // destroyed when corresponding isolate is shut down. To achieve that kernel
-    // isolate needs to receive a message indicating that particular
-    // isolate was shut down. Message should be handled here in this script.
-    compiler = new IncrementalCompiler(fileSystem);
-    isolateCompilers[isolateId] = compiler;
-  }
-  return compiler;
-}
-
 // Process a request from the runtime. See KernelIsolate::CompileToKernel in
 // kernel_isolate.cc and Loader::SendKernelRequest in loader.cc.
 Future _processLoadRequest(request) async {
@@ -162,44 +47,66 @@ Future _processLoadRequest(request) async {
   final SendPort port = request[1];
   final String inputFileUri = request[2];
   final Uri script = Uri.base.resolve(inputFileUri);
-  final bool incremental = request[3];
-
-  final List sourceFiles = request.length > 5 ? request[5] : null;
-
-  Compiler compiler;
-  // TODO(aam): There should be no need to have an option to choose
-  // one compiler or another. We should always use an incremental
-  // compiler as its functionality is a super set of the other one. We need to
-  // watch the performance though.
-  if (incremental) {
-    final int isolateId = request[4];
-    compiler =
-        await lookupOrBuildNewIncrementalCompiler(isolateId, sourceFiles);
-  } else {
-    final FileSystem fileSystem = sourceFiles == null
-        ? PhysicalFileSystem.instance
-        : _buildFileSystem(sourceFiles);
-    compiler = new SingleShotCompiler(
-        fileSystem, sourceFiles == null /* requireMain */);
+
+  FileSystem fileSystem = PhysicalFileSystem.instance;
+  bool requireMain = true;
+
+  if (request.length > 3) {
+    fileSystem = _buildFileSystem(request[3]);
+    requireMain = false;
+  }
+
+  Uri packagesUri = (Platform.packageConfig != null)
+      ? Uri.parse(Platform.packageConfig)
+      : null;
+
+  Uri sdkSummary = Uri.base
+      .resolveUri(new Uri.file(Platform.resolvedExecutable))
+      .resolveUri(new Uri.directory("patched_sdk"))
+      // TODO(sigmund): use outline.dill when the mixin transformer is modular.
+      .resolve('platform.dill');
+
+  if (verbose) {
+    print("DFE: scriptUri: ${script}");
+    print("DFE: Platform.packageConfig: ${Platform.packageConfig}");
+    print("DFE: packagesUri: ${packagesUri}");
+    print("DFE: Platform.resolvedExecutable: ${Platform.resolvedExecutable}");
+    print("DFE: sdkSummary: ${sdkSummary}");
   }
 
+  var errors = <String>[];
+  var options = new CompilerOptions()
+    ..strongMode = strongMode
+    ..fileSystem = fileSystem
+    ..target = new VmFastaTarget(new TargetFlags(strongMode: strongMode))
+    ..packagesFileUri = packagesUri
+    ..sdkSummary = sdkSummary
+    ..verbose = verbose
+    ..throwOnErrors = false
+    ..reportMessages = true
+    ..onError = (CompilationMessage e) {
+      if (e.severity == Severity.error) {
+        // TODO(sigmund): support emitting code with errors as long as they are
+        // handled in the generated code (issue #30194).
+        errors.add(e.message);
+      }
+    };
+
   CompilationResult result;
   try {
-    if (verbose) {
-      print("DFE: scriptUri: ${script}");
-    }
-
-    Program program = await compiler.compile(script);
+    Program program = requireMain
+        ? await kernelForProgram(script, options)
+        : await kernelForBuildUnit([script], options..chaseDependencies = true);
 
-    if (compiler.errors.isNotEmpty) {
+    if (errors.isNotEmpty) {
       // TODO(sigmund): the compiler prints errors to the console, so we
       // shouldn't print those messages again here.
-      result = new CompilationResult.errors(compiler.errors);
+      result = new CompilationResult.errors(errors);
     } else {
       // We serialize the program excluding platform.dill because the VM has
       // these sources built-in. Everything loaded as a summary in
       // [kernelForProgram] is marked `external`, so we can use that bit to
-      // decide what to exclude.
+      // decide what to excluce.
       // TODO(sigmund): remove the following line (Issue #30111)
       program.libraries.forEach((e) => e.isExternal = false);
       result = new CompilationResult.ok(
@@ -259,13 +166,7 @@ train(String scriptUri) {
       throw "Unexpected response: $response";
     }
   };
-  var request = [
-    tag,
-    responsePort.sendPort,
-    scriptUri,
-    1 /* isolateId chosen randomly */,
-    false /* incremental */
-  ];
+  var request = [tag, responsePort.sendPort, scriptUri];
   _processLoadRequest(request);
 }