Set main procedure for Program.

pkg/front_end/test/incremental_kernel_generator_test.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
 
 import 'package:front_end/compiler_options.dart';
 import 'package:front_end/incremental_kernel_generator.dart';
 import 'package:front_end/memory_file_system.dart';
 import 'package:front_end/src/incremental/byte_store.dart';
@@ skipping 54 matching lines @@
 import 'a.dart';
 var b = a;
 ''');
     Uri cUri = writeFile(
         cPath,
         r'''
 import 'a.dart';
 import 'b.dart';
 var c1 = a;
 var c2 = b;
+void main() {}
 ''');
 
     {
       Program program = await getInitialState(cUri);
       _assertLibraryUris(program,
           includes: [aUri, bUri, cUri, Uri.parse('dart:core')]);
       Library library = _getLibrary(program, cUri);
       expect(
           _getLibraryText(library),
           r'''
 library;
 import self as self;
 import "dart:core" as core;
 import "./a.dart" as a;
 import "./b.dart" as b;
 
 static field core::int c1 = a::a;
 static field core::int c2 = b::b;
+static method main() → void {}
 ''');
+      // The main method is set.
+      expect(program.mainMethod, isNotNull);
+      expect(program.mainMethod.enclosingLibrary.fileUri, cUri.toString());
     }
 
     // Update b.dart and recompile c.dart
     writeFile(
         bPath,
         r'''
 import 'a.dart';
 var b = 1.2;
 ''');
     incrementalKernelGenerator.invalidate(bUri);
     {
       DeltaProgram delta = await incrementalKernelGenerator.computeDelta();
       Program program = delta.newProgram;
       _assertLibraryUris(program,
           includes: [bUri, cUri], excludes: [aUri, Uri.parse('dart:core')]);
       Library library = _getLibrary(program, cUri);
       expect(
           _getLibraryText(library),
           r'''
 library;
 import self as self;
 import "dart:core" as core;
 import "./a.dart" as a;
 import "./b.dart" as b;
 
 static field core::int c1 = a::a;
 static field core::double c2 = b::b;
+static method main() → void {}
 ''');
+      // The main method is set even though not the entry point is updated.
+      expect(program.mainMethod, isNotNull);
+      expect(program.mainMethod.enclosingLibrary.fileUri, cUri.toString());
     }
   }
 
   test_compile_export() async {
     writeFile('/test/.packages', 'test:lib/');
     String aPath = '/test/lib/a.dart';
     String bPath = '/test/lib/b.dart';
     String cPath = '/test/lib/c.dart';
     writeFile(aPath, 'class A {}');
     writeFile(bPath, 'export "a.dart";');
@@ skipping 282 matching lines @@
       initialKernelText = _getLibraryText(initialLibrary);
 
       var byteSink = new ByteSink();
       var printer = new LimitedBinaryPrinter(
           byteSink, (library) => library.importUri == bUri);
       printer.writeProgramFile(program);
       bytes = byteSink.builder.takeBytes();
 
       // Remove b.dart from the program.
       // So, the program is now ready for re-adding the library.
+      program.mainMethod = null;
       program.libraries.remove(initialLibrary);
       program.root.removeChild(initialLibrary.importUri.toString());
     }
 
     // Load b.dart from bytes using the initial name root, so that
     // serialized canonical names can be linked to corresponding nodes.
     Library loadedLibrary;
     {
       var programForLoading = new Program(nameRoot: program.root);
       var reader = new BinaryBuilder(bytes);
       reader.readProgram(programForLoading);
       loadedLibrary = _getLibrary(programForLoading, bUri);
     }
 
     // Add the library into the program.
     program.libraries.add(loadedLibrary);
     loadedLibrary.parent = program;
+    program.mainMethod = loadedLibrary.procedures
+        .firstWhere((procedure) => procedure.name.name == 'main');
 
     expect(_getLibraryText(loadedLibrary), initialKernelText);
     verifyProgram(program);
   }
 
   test_updateEntryPoint() async {
     writeFile('/test/.packages', 'test:lib/');
     String path = '/test/lib/test.dart';
     Uri uri = writeFile(
         path,
@@ skipping 232 matching lines @@
     throw fail('No library found with URI "$uri"');
   }
 
   String _getLibraryText(Library library) {
     StringBuffer buffer = new StringBuffer();
     new Printer(buffer, syntheticNames: new NameSystem())
         .writeLibraryFile(library);
     return buffer.toString();
   }
 }