Index: include/clang/ASTMatchers/ASTMatchFinder.h
===================================================================
--- include/clang/ASTMatchers/ASTMatchFinder.h
+++ include/clang/ASTMatchers/ASTMatchFinder.h
@@ -42,6 +42,7 @@
 #define LLVM_CLANG_ASTMATCHERS_ASTMATCHFINDER_H
 
 #include "clang/ASTMatchers/ASTMatchers.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Timer.h"
 
@@ -208,7 +209,7 @@
         NestedNameSpecifierLoc;
     std::vector<std::pair<TypeLocMatcher, MatchCallback *>> TypeLoc;
     /// \brief All the callbacks in one container to simplify iteration.
-    std::vector<MatchCallback *> AllCallbacks;
+    llvm::SmallPtrSet<MatchCallback *, 16> AllCallbacks;
   };
 
 private:
Index: lib/ASTMatchers/ASTMatchFinder.cpp
===================================================================
--- lib/ASTMatchers/ASTMatchFinder.cpp
+++ lib/ASTMatchers/ASTMatchFinder.cpp
@@ -913,37 +913,37 @@
 void MatchFinder::addMatcher(const DeclarationMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.DeclOrStmt.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 void MatchFinder::addMatcher(const TypeMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.Type.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 void MatchFinder::addMatcher(const StatementMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.DeclOrStmt.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 void MatchFinder::addMatcher(const NestedNameSpecifierMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.NestedNameSpecifier.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 void MatchFinder::addMatcher(const NestedNameSpecifierLocMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.NestedNameSpecifierLoc.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 void MatchFinder::addMatcher(const TypeLocMatcher &NodeMatch,
                              MatchCallback *Action) {
   Matchers.TypeLoc.emplace_back(NodeMatch, Action);
-  Matchers.AllCallbacks.push_back(Action);
+  Matchers.AllCallbacks.insert(Action);
 }
 
 bool MatchFinder::addDynamicMatcher(const internal::DynTypedMatcher &NodeMatch,