[analyzer] Fix duplicated excluded globs

With 39c60bc
(https://dart-review.googlesource.com/c/sdk/+/464762) it suddenly took
more than 7 minutes to start the analysis server on my machine.
Turns out it was caused by duplicated exclude globs.

This should fix the issue (and avoid some traversing of the filesystem)
and takes startup back to a more reasonable time.

By applying this patch:

```
diff --git a/pkg/analyzer/lib/src/dart/analysis/analysis_context_collection.dart b/pkg/analyzer/lib/src/dart/analysis/analysis_context_collection.dart
index 72a821c..0c7f8ead5d2 100644
--- a/pkg/analyzer/lib/src/dart/analysis/analysis_context_collection.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/analysis_context_collection.dart
@@ -101,6 +101,10 @@ class AnalysisContextCollectionImpl implements AnalysisContextCollection {
       optionsFile: optionsFile,
       packagesFile: packagesFile,
     );
+    for(var root in roots) {
+      // ignore: avoid_dynamic_calls
+      print("Root with ${(root as dynamic).excludedGlobs.length} globs");
+    }

     byteStore ??= MemoryByteStore();

```

and running

```
out/ReleaseX64/dart-sdk/bin/dart pkg/analysis_server/bin/server.dart --train-using pkg/front_end
```

so I can see the number of excluded globs in each root, before this CL
it printed `Root with 19958 globs`.
With this CL it prins `Root with 34 globs` (which it also did before 39c60bc).

Change-Id: Ie0b5edc7eede4c28394cd3d20334f9f1ad8417d3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/465920
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: jensjoha

pkg/analyzer/lib/src/dart/analysis/context_locator.dart

@@ -404,15 +404,19 @@ class ContextLocatorImpl {
     Set<String> containingRootEnabledLegacyPlugins,
     List<LocatedGlob> excludedGlobs,
     File? optionsFile,
-    File? packagesFile,
-  ) {
+    File? packagesFile, {
+    File? optionsFileFromParentInSameRoot,
+  }) {
     var packagesFileToUse =
         packagesFile ?? _getPackagesFile(folder) ?? containingRoot.packagesFile;
     var buildGnFile = folder.getExistingFile(file_paths.buildGn);
 
     var optionsFileToUse = optionsFile;
     if (optionsFileToUse == null) {
       optionsFileToUse = folder.existingAnalysisOptionsYamlFile;
+      // If this folder doesn't have one use the one from a parent folder if any,
+      // that will be the one we find anyway.
+      optionsFileToUse ??= optionsFileFromParentInSameRoot;
       if (optionsFileToUse == null) {
         var parentFolder = folder.parent;
         while (parentFolder != containingRoot.root) {
@@ -470,12 +474,14 @@ class ContextLocatorImpl {
     if (optionsFileToUse != null) {
       (containingRoot as ContextRootImpl).optionsFileMap[folder] =
           optionsFileToUse;
-      // Add excluded globs.
-      var excludes = _getExcludedGlobs(
-        optionsFileToUse,
-        containingRoot.workspace,
-      );
-      containingRoot.excludedGlobs.addAll(excludes);
+      if (optionsFileToUse != optionsFileFromParentInSameRoot) {
+        // Add excluded globs only if we found a new options file.
+        var excludes = _getExcludedGlobs(
+          optionsFileToUse,
+          containingRoot.workspace,
+        );
+        containingRoot.excludedGlobs.addAll(excludes);
+      }
     }
     _createContextRootsIn(
       roots,
@@ -487,6 +493,7 @@ class ContextLocatorImpl {
       excludedGlobs,
       optionsFile,
       packagesFile,
+      optionsFileToUseForFolder: usedThisRoot ? optionsFileToUse : null,
     );
 
     return usedThisRoot;
@@ -507,8 +514,9 @@ class ContextLocatorImpl {
     Set<String> containingRootEnabledLegacyPlugins,
     List<LocatedGlob> excludedGlobs,
     File? optionsFile,
-    File? packagesFile,
-  ) {
+    File? packagesFile, {
+    File? optionsFileToUseForFolder,
+  }) {
     bool isExcluded(Folder folder) {
       if (excludedFolders.contains(folder) ||
           folder.shortName.startsWith('.')) {
@@ -553,6 +561,7 @@ class ContextLocatorImpl {
               excludedGlobs,
               optionsFile,
               packagesFile,
+              optionsFileFromParentInSameRoot: optionsFileToUseForFolder,
             );
           }
         }

pkg/analyzer/test/src/dart/analysis/analysis_context_collection_test.dart

@@ -6,6 +6,7 @@ import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/analysis_context_collection.dart';
 import 'package:analyzer/src/dart/analysis/analysis_options.dart';
+import 'package:analyzer/src/dart/analysis/context_root.dart';
 import 'package:analyzer/src/dart/analysis/driver_based_analysis_context.dart';
 import 'package:analyzer/src/dart/analysis/experiments.dart';
 import 'package:analyzer/src/dart/analysis/file_state.dart';
@@ -641,7 +642,11 @@ name: test
       name: 'test',
     );
 
-    newAnalysisOptionsYamlFile(testPackageRootPath, '');
+    newAnalysisOptionsYamlFile(testPackageRootPath, r'''
+analyzer:
+  exclude:
+    - foo/**
+''');
     newFile('$testPackageLibPath/a.dart', '');
 
     var nestedPath = '$testPackageLibPath/nested';
@@ -662,7 +667,14 @@ analyzer:
     newFile('$nestedNestedPath/c.dart', '');
     newFile('$nestedNestedPath/excluded2/d.dart', '');
 
-    _assertWorkspaceCollectionText(workspaceRootPath, r'''
+    // There's still an issue here with these exclude globs being there twice:
+    // - foo/** in /home/test
+    // - foo in /home/test
+    // But at least that's it.
+    _assertWorkspaceCollectionText(
+      workspaceRootPath,
+      withExcludedGlobs: true,
+      r'''
 contexts
   /home/test
     packagesFile: /home/test/.dart_tool/package_config.json
@@ -680,6 +692,15 @@ contexts
         uri: package:test/nested/nested/c.dart
         analysisOptions_2
         workspacePackage_0_0
+    excludedGlobs
+      foo/** in /home/test
+      foo in /home/test
+      foo/** in /home/test
+      foo in /home/test
+      excluded/** in /home/test/lib/nested
+      excluded in /home/test/lib/nested
+      excluded2/** in /home/test/lib/nested/nested
+      excluded2 in /home/test/lib/nested/nested
 analysisOptions
   analysisOptions_0: /home/test/analysis_options.yaml
   analysisOptions_1: /home/test/lib/nested/analysis_options.yaml
@@ -690,7 +711,8 @@ workspaces
     pubPackages
       workspacePackage_0_0: PubPackage
         root: /home/test
-''');
+''',
+    );
   }
 
   test_packageConfigWorkspace_multipleAnalysisOptions_outerExclude() async {
@@ -1686,13 +1708,15 @@ workspaces
   void _assertWorkspaceCollectionText(
     String workspaceRootPath,
     String expected, {
+    bool withExcludedGlobs = false,
     File? optionsFile,
     void Function({required AnalysisOptionsImpl analysisOptions})?
     updateAnalysisOptions,
   }) {
     if (optionsFile != null) {
       expect(optionsFile.exists, isTrue);
     }
+    configuration.withExcludedGlobs = withExcludedGlobs;
     var collection = AnalysisContextCollectionImpl(
       resourceProvider: resourceProvider,
       sdkPath: sdkRoot.path,
@@ -1809,6 +1833,13 @@ class _AnalysisContextCollectionPrinter {
           _writeDartFile(fsState, file);
         }
       });
+      if (configuration.withExcludedGlobs && contextRoot is ContextRootImpl) {
+        sink.writeElements('excludedGlobs', contextRoot.excludedGlobs, (glob) {
+          sink.writelnWithIndent(
+            '${glob.glob.pattern} in ${glob.parent.posixPath}',
+          );
+        });
+      }
     });
   }
 
@@ -1944,4 +1975,5 @@ class _AnalysisContextCollectionPrinterConfiguration {
   bool withEnabledFeatures = false;
   bool withLintRules = false;
   bool withOptionFilesForContext = false;
+  bool withExcludedGlobs = false;
 }