diff --git a/clang/lib/Tooling/FileMatchTrie.cpp b/clang/lib/Tooling/FileMatchTrie.cpp
--- a/clang/lib/Tooling/FileMatchTrie.cpp
+++ b/clang/lib/Tooling/FileMatchTrie.cpp
@@ -105,8 +105,13 @@
                            StringRef FileName,
                            bool &IsAmbiguous,
                            unsigned ConsumedLength = 0) const {
+    // Note: we support only directory symlinks for performance reasons.
     if (Children.empty()) {
-      if (Comparator.equivalent(StringRef(Path), FileName))
+      // As far as we do not support file symlinks we compare
+      // basenames here to avoid expensive request to file system.
+      if (llvm::sys::path::filename(Path) ==
+              llvm::sys::path::filename(FileName) &&
+          Comparator.equivalent(StringRef(Path), FileName))
         return StringRef(Path);
       return {};
     }
@@ -121,6 +126,15 @@
       if (!Result.empty() || IsAmbiguous)
         return Result;
     }
+
+    // We failed to find the file with `Children.find()`.
+    // If `ConsumedLength` is equal to 0 then we have tried to find the file
+    // with it's basename. Thus, we do not have files with the same
+    // basename and could return empty result here as far as we
+    // do not support file symlinks.
+    if (ConsumedLength == 0)
+      return {};
+
     std::vector<StringRef> AllChildren;
     getAll(AllChildren, MatchingChild);
     StringRef Result;
diff --git a/clang/unittests/Tooling/CompilationDatabaseTest.cpp b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
--- a/clang/unittests/Tooling/CompilationDatabaseTest.cpp
+++ b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
@@ -281,6 +281,15 @@
   EXPECT_EQ("Cannot resolve relative paths", Error);
 }
 
+TEST_F(FileMatchTrieTest, SingleFile) {
+  Trie.insert("/root/RootFile.cc");
+  EXPECT_EQ("", find("/root/rootfile.cc"));
+  // Add subpath to avoid `if (Children.empty())` special case
+  // which we hit at previous `find()`.
+  Trie.insert("/root/otherpath/OtherFile.cc");
+  EXPECT_EQ("", find("/root/rootfile.cc"));
+}
+
 TEST(findCompileArgsInJsonDatabase, FindsNothingIfEmpty) {
   std::string ErrorMessage;
   CompileCommand NotFound = findCompileArgsInJsonDatabase(