blob: f22f9923e756fc2a009cfc263ecd2128b75b061a [file] [log] [blame]
// 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/src/api_prototype/dependency_grapher.dart';
import 'package:front_end/src/async_dependency_walker.dart';
import 'package:front_end/src/base/processed_options.dart';
import 'package:front_end/src/fasta/parser.dart';
import 'package:front_end/src/fasta/scanner.dart';
import 'package:front_end/src/fasta/source/directive_listener.dart';
import 'package:front_end/src/fasta/uri_translator.dart';
/// Generates a representation of the dependency graph of a program.
///
/// Given the Uri of one or more files, this function follows `import`,
/// `export`, and `part` declarations to discover a graph of all files involved
/// in the program.
///
/// If a [fileReader] is supplied, it is used to read file contents; otherwise
/// they are read directly from `options.fileSystem`.
///
/// This is intended for internal use by the front end. Clients should use
/// package:front_end/src/api_prototype/dependency_grapher.dart.
Future<Graph> graphForProgram(List<Uri> sources, ProcessedOptions options,
{FileReader fileReader}) async {
UriTranslator uriTranslator = await options.getUriTranslator();
fileReader ??= (originalUri, resolvedUri) =>
options.fileSystem.entityForUri(resolvedUri).readAsString();
var walker = new _Walker(fileReader, uriTranslator, options.compileSdk);
var startingPoint = new _StartingPoint(walker, sources);
await walker.walk(startingPoint);
return walker.graph;
}
/// Type of the callback function used by [graphForProgram] to read file
/// contents.
typedef Future<String> FileReader(Uri originalUri, Uri resolvedUri);
class _StartingPoint extends _WalkerNode {
final List<Uri> sources;
_StartingPoint(_Walker walker, this.sources) : super(walker, null);
@override
Future<List<_WalkerNode>> computeDependencies() async =>
sources.map(walker.nodeForUri).toList();
}
class _Walker extends AsyncDependencyWalker<_WalkerNode> {
final FileReader fileReader;
final UriTranslator uriTranslator;
final _nodesByUri = <Uri, _WalkerNode>{};
final graph = new Graph();
final bool compileSdk;
_Walker(this.fileReader, this.uriTranslator, this.compileSdk);
@override
Future<Null> evaluate(_WalkerNode v) {
if (v is _StartingPoint) return new Future.value();
return evaluateScc([v]);
}
@override
Future<Null> evaluateScc(List<_WalkerNode> scc) {
var cycle = new LibraryCycleNode();
for (var walkerNode in scc) {
cycle.libraries[walkerNode.uri] = walkerNode.library;
}
graph.topologicallySortedCycles.add(cycle);
return new Future.value();
}
_WalkerNode nodeForUri(Uri referencedUri) {
var dependencyNode = _nodesByUri.putIfAbsent(
referencedUri, () => new _WalkerNode(this, referencedUri));
return dependencyNode;
}
}
class _WalkerNode extends Node<_WalkerNode> {
static final dartCoreUri = Uri.parse('dart:core');
final _Walker walker;
final Uri uri;
final LibraryNode library;
_WalkerNode(this.walker, Uri uri)
: uri = uri,
library = new LibraryNode(uri);
@override
Future<List<_WalkerNode>> computeDependencies() async {
var dependencies = <_WalkerNode>[];
// TODO(paulberry): add error recovery if the file can't be read.
var resolvedUri = uri.scheme == 'dart' || uri.scheme == 'package'
? walker.uriTranslator.translate(uri)
: uri;
if (resolvedUri == null) {
// TODO(paulberry): If an error reporter was provided, report the error
// in the proper way and continue.
throw new StateError('Invalid URI: $uri');
}
var contents = await walker.fileReader(uri, resolvedUri);
var scannerResults = scanString(contents);
// TODO(paulberry): report errors.
var listener = new DirectiveListener();
new TopLevelParser(listener).parseUnit(scannerResults.tokens);
bool coreUriFound = false;
void handleDependency(Uri referencedUri) {
_WalkerNode dependencyNode = walker.nodeForUri(referencedUri);
library.dependencies.add(dependencyNode.library);
if (referencedUri.scheme != 'dart' || walker.compileSdk) {
dependencies.add(dependencyNode);
}
if (referencedUri == dartCoreUri) {
coreUriFound = true;
}
}
for (var part in listener.parts) {
// TODO(paulberry): when we support SDK libraries, we'll need more
// complex logic here to find SDK parts correctly.
library.parts.add(uri.resolve(part));
}
for (var dep in listener.imports) {
handleDependency(uri.resolve(dep.uri));
}
for (var dep in listener.exports) {
handleDependency(uri.resolve(dep.uri));
}
if (!coreUriFound) {
handleDependency(dartCoreUri);
}
return dependencies;
}
}