diff --git a/clang/include/clang/Tooling/CompilationDatabasePluginRegistry.h b/clang/include/clang/Tooling/CompilationDatabasePluginRegistry.h
--- a/clang/include/clang/Tooling/CompilationDatabasePluginRegistry.h
+++ b/clang/include/clang/Tooling/CompilationDatabasePluginRegistry.h
@@ -34,6 +34,10 @@
   /// \see CompilationDatabase::loadFromDirectory().
   virtual std::unique_ptr<CompilationDatabase>
   loadFromDirectory(StringRef Directory, std::string &ErrorMessage) = 0;
+
+  /// Used to sort the plugins before attempting to load. Plugins with a lower
+  /// value here will run over a directory first.
+  virtual unsigned getPriority() const = 0;
 };
 
 using CompilationDatabasePluginRegistry =
diff --git a/clang/lib/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -64,14 +64,26 @@
 CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
                                        std::string &ErrorMessage) {
   llvm::raw_string_ostream ErrorStream(ErrorMessage);
+  using NameAndPlugin =
+      std::pair<StringRef, std::unique_ptr<CompilationDatabasePlugin>>;
+  llvm::SmallVector<NameAndPlugin, 4> Plugins;
+
   for (const CompilationDatabasePluginRegistry::entry &Database :
        CompilationDatabasePluginRegistry::entries()) {
+    Plugins.emplace_back(Database.getName(), Database.instantiate());
+  }
+  llvm::sort(Plugins, [](const NameAndPlugin &LHS, const NameAndPlugin &RHS) {
+    assert(LHS.second->getPriority() != RHS.second->getPriority() &&
+           "Undeterministic priority");
+    return LHS.second->getPriority() < RHS.second->getPriority();
+  });
+  for (auto &Plugin : Plugins) {
     std::string DatabaseErrorMessage;
-    std::unique_ptr<CompilationDatabasePlugin> Plugin(Database.instantiate());
     if (std::unique_ptr<CompilationDatabase> DB =
-            Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
+            Plugin.second->loadFromDirectory(BuildDirectory,
+                                             DatabaseErrorMessage))
       return DB;
-    ErrorStream << Database.getName() << ": " << DatabaseErrorMessage << "\n";
+    ErrorStream << Plugin.first << ": " << DatabaseErrorMessage << "\n";
   }
   return nullptr;
 }
@@ -405,6 +417,12 @@
     llvm::sys::path::append(DatabasePath, "compile_flags.txt");
     return FixedCompilationDatabase::loadFromFile(DatabasePath, ErrorMessage);
   }
+
+  unsigned int getPriority() const override {
+    // Give this a high value as it should be the fallback and any other Plugin
+    // should be used first.
+    return 100;
+  }
 };
 
 } // namespace
diff --git a/clang/lib/Tooling/JSONCompilationDatabase.cpp b/clang/lib/Tooling/JSONCompilationDatabase.cpp
--- a/clang/lib/Tooling/JSONCompilationDatabase.cpp
+++ b/clang/lib/Tooling/JSONCompilationDatabase.cpp
@@ -173,6 +173,13 @@
                           std::move(Base), llvm::vfs::getRealFileSystem())))
                 : nullptr;
   }
+
+  unsigned int getPriority() const override {
+    // Pretty arbitrary. However we want to leave room for database sources
+    // which could have a higher priority, like directly supporting ninja or
+    // make files.
+    return 50;
+  }
 };
 
 } // namespace