Rework DillLoader to allow adding multiple dills.

This allows us to compose a consistent bundle with SDK and the transitive
closure of required libraries for a libarary, and then compile it
separately (or as a part of its own library cycle).

There is still more data public than I'd like, but I will leave this
clean up fo later.

R=ahe@google.com, kmillikin@google.com, paulberry@google.com, sigmund@google.com
BUG=

Review-Url: https://codereview.chromium.org/2872903005 .

pkg/front_end/lib/src/fasta/dill/dill_loader.dart

@@ -6,47 +6,39 @@ library fasta.dill_loader;
 
 import 'dart:async' show Future;
 
-import 'dart:io' show File;
-
-import 'package:kernel/kernel.dart' show loadProgramFromBinary;
-
 import 'package:kernel/ast.dart' show Library, Program;
 
 import '../loader.dart' show Loader;
-
 import '../target_implementation.dart' show TargetImplementation;
-
 import 'dill_library_builder.dart' show DillLibraryBuilder;
 
 class DillLoader extends Loader<Library> {
-  Uri input;
-
   Program program;
 
   DillLoader(TargetImplementation target) : super(target);
 
-  DillLibraryBuilder read(Uri uri, [Uri fileUri]) => super.read(uri, fileUri);
-
-  Future<Null> buildOutline(DillLibraryBuilder builder) async {
-    if (program == null) {
-      byteCount = await new File.fromUri(input).length();
-      setProgram(await loadProgramFromBinary(input.toFilePath()));
+  /// Append compiled libraries from the given [program]. If the [filter] is
+  /// provided, append only libraries whose [Uri] is accepted by the [filter].
+  void appendLibraries(Program program, [bool filter(Uri uri)]) {
+    this.program ??= new Program();
+    program.unbindCanonicalNames();
+    for (Library library in program.libraries) {
+      if (filter == null || filter(library.importUri)) {
+        this.program.libraries.add(library);
+        read(library.importUri).library = library;
+      }
     }
-    builder.library.classes.forEach(builder.addClass);
-    builder.library.procedures.forEach(builder.addMember);
-    builder.library.fields.forEach(builder.addMember);
   }
 
   Future<Null> buildBody(DillLibraryBuilder builder) {
     return buildOutline(builder);
   }
 
-  void setProgram(Program program) {
-    assert(input != null);
-    this.program = program;
-    program.unbindCanonicalNames();
-    for (Library library in program.libraries) {
-      read(library.importUri).library = library;
-    }
+  Future<Null> buildOutline(DillLibraryBuilder builder) async {
+    builder.library.classes.forEach(builder.addClass);
+    builder.library.procedures.forEach(builder.addMember);
+    builder.library.fields.forEach(builder.addMember);
   }
+
+  DillLibraryBuilder read(Uri uri, [Uri fileUri]) => super.read(uri, fileUri);
 }

pkg/front_end/lib/src/fasta/dill/dill_target.dart

@@ -10,7 +10,7 @@ import 'package:kernel/ast.dart' show Class;
 
 import 'dill_loader.dart' show DillLoader;
 
-import '../errors.dart' show inputError, internalError;
+import '../errors.dart' show internalError;
 
 import '../target_implementation.dart' show TargetImplementation;
 
@@ -37,11 +37,7 @@ class DillTarget extends TargetImplementation {
   }
 
   void read(Uri uri) {
-    if (loader.input == null) {
-      loader.input = uri;
-    } else {
-      inputError(uri, -1, "Can only read one dill file.");
-    }
+    internalError("Unsupported operation.");
   }
 
   Future<Null> writeProgram(Uri uri) {
@@ -49,7 +45,7 @@ class DillTarget extends TargetImplementation {
   }
 
   Future<Null> writeOutline(Uri uri) async {
-    if (loader.input == null) return null;
+    if (loader.program == null) return null;
     await loader.buildOutlines();
     isLoaded = true;
     return null;

pkg/front_end/lib/src/fasta/fasta.dart

@@ -14,7 +14,7 @@ import 'package:front_end/physical_file_system.dart';
 import 'package:kernel/binary/ast_to_binary.dart'
     show LibraryFilteringBinaryPrinter;
 
-import 'package:kernel/kernel.dart' show Program, Library;
+import 'package:kernel/kernel.dart' show Library, Program, loadProgramFromBytes;
 
 import 'package:kernel/target/targets.dart' show Target, TargetFlags, getTarget;
 
@@ -180,7 +180,7 @@ Future<CompilationResult> parseScript(
           await TranslateUri.parse(PhysicalFileSystem.instance, null, packages);
       final Ticker ticker = new Ticker(isVerbose: verbose);
       final DillTarget dillTarget = new DillTarget(ticker, uriTranslator);
-      dillTarget.read(patchedSdk.resolve('platform.dill'));
+      _appendDillForUri(dillTarget, patchedSdk.resolve('platform.dill'));
       final KernelTarget kernelTarget = new KernelTarget(
           PhysicalFileSystem.instance, dillTarget, uriTranslator, strongMode);
       kernelTarget.read(fileName);
@@ -250,8 +250,8 @@ Future writeDepsFile(Uri script, Uri depsFile, Uri output,
     TranslateUri uriTranslator = await TranslateUri.parse(
         c.fileSystem, c.options.sdk, c.options.packages);
     ticker.logMs("Read packages file");
-    DillTarget dillTarget = new DillTarget(ticker, uriTranslator)
-      ..read(platform);
+    DillTarget dillTarget = new DillTarget(ticker, uriTranslator);
+    _appendDillForUri(dillTarget, platform);
     KernelTarget kernelTarget = new KernelTarget(PhysicalFileSystem.instance,
         dillTarget, uriTranslator, false, c.uriToSource);
 
@@ -263,6 +263,14 @@ Future writeDepsFile(Uri script, Uri depsFile, Uri output,
   });
 }
 
+/// Load the [Program] from the given [uri] and append its libraries
+/// to the [dillTarget].
+void _appendDillForUri(DillTarget dillTarget, Uri uri) {
+  var bytes = new File.fromUri(uri).readAsBytesSync();
+  var platformProgram = loadProgramFromBytes(bytes);
+  dillTarget.loader.appendLibraries(platformProgram);
+}
+
 // TODO(ahe): https://github.com/dart-lang/sdk/issues/28316
 class ByteSink implements Sink<List<int>> {
   final BytesBuilder builder = new BytesBuilder();

pkg/front_end/test/fasta/testing/suite.dart

@@ -193,9 +193,7 @@ class Outline extends Step<TestDescription, Program, FastaContext> {
     Program platform = await context.loadPlatform();
     Ticker ticker = new Ticker();
     DillTarget dillTarget = new DillTarget(ticker, context.uriTranslator);
-    dillTarget.loader
-      ..input = Uri.parse("org.dartlang:platform") // Make up a name.
-      ..setProgram(platform);
+    dillTarget.loader.appendLibraries(platform);
     KernelTarget sourceTarget = astKind == AstKind.Analyzer
         ? new AnalyzerTarget(dillTarget, context.uriTranslator, strongMode)
         : new KernelTarget(PhysicalFileSystem.instance, dillTarget,

pkg/kernel/lib/kernel.dart

@@ -23,8 +23,13 @@ import 'text/ast_to_text.dart';
 export 'ast.dart';
 
 Program loadProgramFromBinary(String path, [Program program]) {
+  List<int> bytes = new File(path).readAsBytesSync();
+  return loadProgramFromBytes(bytes, program);
+}
+
+Program loadProgramFromBytes(List<int> bytes, [Program program]) {
   program ??= new Program();
-  new BinaryBuilder(new File(path).readAsBytesSync()).readProgram(program);
+  new BinaryBuilder(bytes).readProgram(program);
   return program;
 }
 

pkg/kernel/test/closures/suite.dart

@@ -93,9 +93,7 @@ class FastaCompile
     Program platform = await context.loadPlatform();
     Ticker ticker = new Ticker();
     DillTarget dillTarget = new DillTarget(ticker, context.uriTranslator);
-    dillTarget.loader
-      ..input = Uri.parse("org.dartlang:platform") // Make up a name.
-      ..setProgram(platform);
+    dillTarget.loader.appendLibraries(platform);
     KernelTarget sourceTarget = new KernelTarget(PhysicalFileSystem.instance,
         dillTarget, context.uriTranslator, context.strongMode);
 

pkg/kernel/test/interpreter/suite.dart

@@ -76,9 +76,7 @@ class FastaCompile extends Step<TestDescription, Program, InterpreterContext> {
     Program platform = await context.loadPlatform();
     Ticker ticker = new Ticker();
     DillTarget dillTarget = new DillTarget(ticker, context.uriTranslator);
-    dillTarget.loader
-      ..input = Uri.parse("org.dartlang:platform") // Make up a name.
-      ..setProgram(platform);
+    dillTarget.loader.appendLibraries(platform);
     KernelTarget sourceTarget = new KernelTarget(PhysicalFileSystem.instance,
         dillTarget, context.uriTranslator, context.strongMode);