Automatically detect 'blaze' or 'bazel' symlink prefix.

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

 // Copyright (c) 2016, 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.src.generated.bazel;
 
 import 'dart:collection';
 import 'dart:core';
 
 import 'package:analyzer/file_system/file_system.dart';
@@ skipping 159 matching lines @@
   File getFile(String pathInWorkspace) {
     return provider.getFile(provider.pathContext.join(root, pathInWorkspace));
   }
 
   /**
    * Find the Bazel workspace that contains the given [path].
    *
    * Return `null` if a workspace markers, such as the `WORKSPACE` file, or
    * the sibling `READONLY` folder cannot be found.
    *
-   * The [symlinkPrefix] is the prefix for names of symlinks like `bazel-bin`,
-   * `bazel-genfiles`, etc.
+   * Return `null` if the workspace does not have `bazel-genfiles` or
+   * `blaze-genfiles` folders, so we don't know where to search generated files.
    */
   static BazelWorkspace find(ResourceProvider provider, String path,
-      {String symlinkPrefix: 'bazel', String readonlySuffix}) {
+      {String readonlySuffix}) {
     Context context = provider.pathContext;
 
     // Ensure that the path is absolute and normalized.
     if (!context.isAbsolute(path)) {
       throw new ArgumentError('not absolute: $path');
     }
     path = context.normalize(path);
 
     Folder folder = provider.getFolder(path);
     while (true) {
       Folder parent = folder.parent;
       if (parent == null) {
         return null;
       }
 
       // Found the READONLY folder, must be a git-based workspace.
       if (readonlySuffix != null) {
         Folder readonlyFolder = parent.getChildAssumingFolder(_READONLY);
         if (readonlyFolder.exists) {
           String root = folder.path;
           String readonly = readonlyFolder.path;
+          String symlinkPrefix = _findSymlinkPrefix(provider, root);
+          if (symlinkPrefix == null) {
+            return null;
+          }
           return new BazelWorkspace._(
               provider,
               root,
               context.join(readonly, readonlySuffix),
               context.join(root, '$symlinkPrefix-bin'),
               context.join(root, '$symlinkPrefix-genfiles'));
         }
       }
 
       // Found the WORKSPACE file, must be a non-git workspace.
       if (folder.getChildAssumingFile(_WORKSPACE).exists) {
         String root = folder.path;
+        String symlinkPrefix = _findSymlinkPrefix(provider, root);
+        if (symlinkPrefix == null) {
+          return null;
+        }
         return new BazelWorkspace._(
             provider,
             root,
             null,
             context.join(root, '$symlinkPrefix-bin'),
             context.join(root, '$symlinkPrefix-genfiles'));
       }
 
       // Go up the folder.
       folder = parent;
     }
   }
+
+  /**
+   * Return the symlink prefix for folders `X-bin` or `X-genfiles` by probing
+   * the internal `blaze-genfiles` and `bazel-genfiles`. Return `null` if
+   * neither of the folders exists.
+   */
+  static String _findSymlinkPrefix(ResourceProvider provider, String root) {
+    Context context = provider.pathContext;
+    if (provider.getFolder(context.join(root, 'blaze-genfiles')).exists) {
+      return 'blaze';
+    }
+    if (provider.getFolder(context.join(root, 'bazel-genfiles')).exists) {
+      return 'bazel';
+    }
+    return null;
+  }
 }