Index: include/clang/Parse/Parser.h
===================================================================
--- include/clang/Parse/Parser.h
+++ include/clang/Parse/Parser.h
@@ -2965,6 +2965,10 @@
   void CodeCompleteMacroArgument(IdentifierInfo *Macro, MacroInfo *MacroInfo,
                                  unsigned ArgumentIndex) override;
   void CodeCompleteNaturalLanguage() override;
+
+  /// Gets set to true after calling CodeCompleteCall, it is for a hack to make
+  /// signature help working even when it is triggered inside a token.
+  bool CalledOverloadCompletion = false;
 };
 
 }  // end namespace clang
Index: lib/Parse/ParseExpr.cpp
===================================================================
--- lib/Parse/ParseExpr.cpp
+++ lib/Parse/ParseExpr.cpp
@@ -1648,6 +1648,10 @@
                 Actions.CodeCompleteCall(getCurScope(), LHS.get(), ArgExprs);
              })) {
             (void)Actions.CorrectDelayedTyposInExpr(LHS);
+            if (PP.isCodeCompletionReached() && !CalledOverloadCompletion) {
+              Actions.CodeCompleteCall(getCurScope(), LHS.get(), ArgExprs);
+              CalledOverloadCompletion = true;
+            }
             LHS = ExprError();
           } else if (LHS.isInvalid()) {
             for (auto &E : ArgExprs)
@@ -2813,6 +2817,7 @@
         Completer();
       else
         Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
+      CalledOverloadCompletion = true;
       cutOffParsing();
       return true;
     }