CLI support for embedders (#25380).

pkg/analyzer_cli/lib/src/driver.dart

 // Copyright (c) 2015, 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.
 
 library analyzer_cli.src.driver;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer/file_system/file_system.dart' as fileSystem;
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/plugin/options.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
+import 'package:analyzer/source/embedder.dart';
 import 'package:analyzer/source/package_map_provider.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/source/pub_package_map_provider.dart';
 import 'package:analyzer/source/sdk_ext.dart';
 import 'package:analyzer/src/generated/constant.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/interner.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
@@ skipping 270 matching lines @@
         }
       } else {
         return true;
       }
     };
   }
 
   /// Decide on the appropriate method for resolving URIs based on the given
   /// [options] and [customUrlMappings] settings, and return a
   /// [SourceFactory] that has been configured accordingly.
-  SourceFactory _chooseUriResolutionPolicy(CommandLineOptions options) {
+  SourceFactory _chooseUriResolutionPolicy(
+      CommandLineOptions options, AnalysisContext context) {

[Brian Wilkerson, 2016/01/26 19:12:33]

Given that the only thing we need from the context is the embedderYamlLocator,
perhaps we should just pass it in directly. I'm concerned that passing the
context in to a method used to configure the context will lead to errors when
someone thinks they have a fully initialized context. Maybe I'm being overly
cautions.

[pquitslund, 2016/01/26 19:22:19]

Done.

     Packages packages;
     Map<String, List<fileSystem.Folder>> packageMap;
     UriResolver packageUriResolver;
 
     // Process options, caching package resolution details.
     if (options.packageConfigPath != null) {
       String packageConfigPath = options.packageConfigPath;
       Uri fileUri = new Uri.file(packageConfigPath);
       try {
         File configFile = new File.fromUri(fileUri).absolute;
@@ skipping 33 matching lines @@
         // If it failed, that's not a problem; it simply means we have no way
         // to resolve packages.
         if (packageMapInfo.packageMap != null) {
           packageUriResolver = new PackageMapUriResolver(
               PhysicalResourceProvider.INSTANCE, packageMap);
         }
       }
     }
 
     // Now, build our resolver list.
+    List<UriResolver> resolvers = [];
 
     // 'dart:' URIs come first.
-    List<UriResolver> resolvers = [new DartUriResolver(sdk)];
+
+    // Setup embedding.
+    EmbedderYamlLocator yamlLocator =
+        (context as InternalAnalysisContext).embedderYamlLocator;
+    yamlLocator.refresh(packageMap);
+
+    EmbedderUriResolver embedderUriResolver =
+        new EmbedderUriResolver(yamlLocator.embedderYamls);
+    if (embedderUriResolver.length == 0) {
+      // The embedder uri resolver has no mappings. Use the default Dart SDK
+      // uri resolver.
+      resolvers.add(new DartUriResolver(sdk));
+    } else {
+      // The embedder uri resolver has mappings, use it instead of the default
+      // Dart SDK uri resolver.
+      resolvers.add(embedderUriResolver);
+    }
 
     // Next SdkExts.
     if (packageMap != null) {
       resolvers.add(new SdkExtUriResolver(packageMap));
     }
 
     // Then package URIs.
     if (packageUriResolver != null) {
       resolvers.add(packageUriResolver);
     }
@@ skipping 22 matching lines @@
     return new FileBasedSource(sourceFile, uri);
   }
 
   /// Create an analysis context that is prepared to analyze sources according
   /// to the given [options], and store it in [_context].
   void _createAnalysisContext(CommandLineOptions options) {
     if (_canContextBeReused(options)) {
       return;
     }
     _previousOptions = options;
+
+    // Create a context.
+    AnalysisContext context = AnalysisEngine.instance.createAnalysisContext();
+
     // Choose a package resolution policy and a diet parsing policy based on
     // the command-line options.
-    SourceFactory sourceFactory = _chooseUriResolutionPolicy(options);
+    SourceFactory sourceFactory = _chooseUriResolutionPolicy(options, context);
     AnalyzeFunctionBodiesPredicate dietParsingPolicy =
         _chooseDietParsingPolicy(options);
-    // Create a context using these policies.
-    AnalysisContext context = AnalysisEngine.instance.createAnalysisContext();
 
     context.sourceFactory = sourceFactory;
 
     Map<String, String> definedVariables = options.definedVariables;
     if (!definedVariables.isEmpty) {
       DeclaredVariables declaredVariables = context.declaredVariables;
       definedVariables.forEach((String variableName, String value) {
         declaredVariables.define(variableName, value);
       });
     }
@@ skipping 228 matching lines @@
     for (var package in packages) {
       var packageName = path.basename(package.path);
       var realPath = package.resolveSymbolicLinksSync();
       result[packageName] = [
         PhysicalResourceProvider.INSTANCE.getFolder(realPath)
       ];
     }
     return result;
   }
 }