[PATCH] Fix for bug 27802 misc-macro-parentheses breaks variadic macros

[madsravn]

Summary

This is fix for bug 27802: https://llvm.org/bugs/show_bug.cgi?id=27802

I have added a check to clang-tidy which refrains from putting parantheses around macros which are variadic.

[alexfh]

lg

[madsravn]

Code committed.

clang-tidy/misc/MacroParenthesesCheck.cpp

for (auto TI = MI->tokens_begin(), TE = MI->tokens_end(); TI != TE; ++TI) {
     if (PP->getLangOpts().CPlusPlus && Prev.isOneOf(tok::comma, tok::less) &&
         Next.isOneOf(tok::comma, tok::greater))
       continue;
 
     // Namespaces.
     if (Prev.is(tok::kw_namespace))
       continue;
 
+    // Variadic templates
+    if (MI->isVariadic())
+      continue;
+
     Check->diag(Tok.getLocation(), "macro argument should be enclosed in "
                                    "parentheses")
         << FixItHint::CreateInsertion(Tok.getLocation(), "(")
         << FixItHint::CreateInsertion(Tok.getLocation().getLocWithOffset(
                                           PP->getSpelling(Tok).length()),
                                       ")");
   }
 }

test/clang-tidy/misc-macro-parentheses.cpp

 #define GOOD21(a)         case Fred::a:
 #define GOOD22(a)         if (verbose) return a;
 #define GOOD23(type)      (type::Field)
 #define GOOD24(t)         std::set<t> s
 #define GOOD25(t)         std::set<t,t,t> s
 #define GOOD26(x)         (a->*x)
 #define GOOD27(x)         (a.*x)
 #define GOOD28(x)         namespace x {int b;}
+#define GOOD29(...)       std::cout << __VA_ARGS__;
+#define GOOD30(args...)   std::cout << args;
 
 // These are allowed for now..
 #define MAYBE1            *12.34
 #define MAYBE2            <<3