[clangd] Deduplicate query scopes.

Summary:
For example, when anonymous namespace is present, duplicated namespaces might be
generated for the enclosing namespace.

Reviewers: ilya-biryukov

Subscribers: MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D54105

llvm-svn: 346224

1 files changed, 6 insertions, 8 deletions

diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
index fec91e12ead..c79f0171761 100644
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -541,16 +541,14 @@ struct SpecifiedScope {
   // Set if the qualifier is not fully resolved by Sema.
   Optional<std::string> UnresolvedQualifier;
 
-  // Construct scopes being queried in indexes.
+  // Construct scopes being queried in indexes. The results are deduplicated.
   // This method format the scopes to match the index request representation.
   std::vector<std::string> scopesForIndexQuery() {
-    std::vector<std::string> Results;
-    for (StringRef AS : AccessibleScopes) {
-      Results.push_back(AS);
-      if (UnresolvedQualifier)
-        Results.back() += *UnresolvedQualifier;
-    }
-    return Results;
+    std::set<std::string> Results;
+    for (StringRef AS : AccessibleScopes)
+      Results.insert(
+          ((UnresolvedQualifier ? *UnresolvedQualifier : "") + AS).str());
+    return {Results.begin(), Results.end()};
   }
 };