Parse the 'patches' argument in SDK libraries declarations.

pkg/analyzer/lib/src/generated/sdk.dart

Index: pkg/analyzer/lib/src/generated/sdk.dart
diff --git a/pkg/analyzer/lib/src/generated/sdk.dart b/pkg/analyzer/lib/src/generated/sdk.dart
index 7e86d8d965d7f70506c9bfe6da1045f51ab1f55b..8ae3ef8e4a254872195b14c2245bcd797f53c404 100644
--- a/pkg/analyzer/lib/src/generated/sdk.dart
+++ b/pkg/analyzer/lib/src/generated/sdk.dart
@@ -274,6 +274,7 @@ class SdkDescription {
       buffer.write(optionName);
       needsSeparator = true;
     }
+
     for (String path in paths) {
       add(path);
     }
@@ -308,6 +309,11 @@ class SdkLibrariesReader_LibraryBuilder extends RecursiveAstVisitor<Object> {
   static String _DART2JS_PATH = "dart2jsPath";
 
   /**
+   * The name of the `dart2js` platform.
+   */
+  static String _DART2JS_PLATFORM = 'DART2JS_PLATFORM';
+
+  /**
    * The name of the optional parameter used to indicate whether the library is
    * documented.
    */
@@ -320,6 +326,12 @@ class SdkLibrariesReader_LibraryBuilder extends RecursiveAstVisitor<Object> {
   static String _CATEGORIES = "categories";
 
   /**
+   * The name of the optional parameter used to specify the patches for
+   * the library.
+   */
+  static String _PATCHES = "patches";
+
+  /**
    * The name of the optional parameter used to specify the platforms on which
    * the library can be used.
    */
@@ -397,6 +409,17 @@ class SdkLibrariesReader_LibraryBuilder extends RecursiveAstVisitor<Object> {
             library._implementation = (expression as BooleanLiteral).value;
           } else if (name == _DOCUMENTED) {
             library.documented = (expression as BooleanLiteral).value;
+          } else if (name == _PATCHES) {
+            if (expression is MapLiteral) {
+              expression.entries.forEach((MapLiteralEntry entry) {
+                Expression key = entry.key;
+                Expression value = entry.value;
+                if (key is SimpleIdentifier && value is SimpleStringLiteral) {

[Paul Berry, 2016/10/10 19:14:38]

Two issues:

1. The "patches" parameter should be a Map<int, List<String>>, where the list is
a list of paths to patch files.  (This is necessary to accommodate the VM, which
has multiple patches per library).  This code is treating it as a Map<int,
String>.

2. In the long term we'll need to accept keys of the form `PLATFORM1 | PLATFORM2
| PLATFORM3` (so that we can share most patch files between Dart2js and DDC). 
If you just want to add a TODO comment for now, that's fine with me.

[scheglov, 2016/10/10 19:41:52]

OK, I see now.
The key of this map must be a combination of platforms.
Done.

+                  int platform = _convertPlatform(key.name);
+                  library.addPatch(platform, value.value);
+                }
+              });
+            }
           } else if (name == _PLATFORMS) {
             if (expression is SimpleIdentifier) {
               String identifier = expression.name;
@@ -417,6 +440,20 @@ class SdkLibrariesReader_LibraryBuilder extends RecursiveAstVisitor<Object> {
     }
     return null;
   }
+
+  /**
+   * Return the platform constant value for the [name].  Throw [ArgumentError]
+   * if the given [name] is not a valid platform name.
+   */
+  static int _convertPlatform(String name) {
+    if (name == _DART2JS_PLATFORM) {
+      return SdkLibraryImpl.DART2JS_PLATFORM;
+    }
+    if (name == _VM_PLATFORM) {
+      return SdkLibraryImpl.VM_PLATFORM;
+    }
+    throw new ArgumentError('Invalid platform name: $name');
+  }
 }
 
 /**
@@ -469,6 +506,12 @@ abstract class SdkLibrary {
    * including `dart:`.
    */
   String get shortName;
+
+  /**
+   * Return the list of paths to the patch files that should be applied
+   * to this library for the given [platform], not `null`.
+   */
+  List<String> getPatches(int platform);
 }
 
 /**
@@ -521,6 +564,12 @@ class SdkLibraryImpl implements SdkLibrary {
   int _platforms = 0;
 
   /**
+   * The mapping from the platform to the list of patches that should be
+   * applied for this library.
+   */
+  final Map<int, List<String>> _patches = new HashMap<int, List<String>>();
+
+  /**
    * Initialize a newly created library to represent the library with the given
    * [name].
    */
@@ -552,6 +601,20 @@ class SdkLibraryImpl implements SdkLibrary {
   bool get isVmLibrary => (_platforms & VM_PLATFORM) != 0;
 
   /**
+   * Add a new patch with the given [path] that should be applied for the
+   * given [platform].
+   */
+  void addPatch(int platform, String path) {
+    assert(path != null);
+    _patches.putIfAbsent(platform, () => <String>[]).add(path);
+  }
+
+  @override
+  List<String> getPatches(int platform) {
+    return _patches[platform] ?? const <String>[];
+  }
+
+  /**
    * Record that this library can be compiled to JavaScript by dart2js.
    */
   void setDart2JsLibrary() {