[clang-tidy] readability-named-parameter: don't complain about implicit parameters

Fixes http://llvm.org/PR24464.

llvm-svn: 252248

clang-tools-extra/clang-tidy/readability/NamedParameterCheck.cpp

@@ -45,6 +45,8 @@ void NamedParameterCheck::check(const MatchFinder::MatchResult &Result) {
   //       arguments in the same position.
   for (unsigned I = 0, E = Function->getNumParams(); I != E; ++I) {
     const ParmVarDecl *Parm = Function->getParamDecl(I);
+    if (Parm->isImplicit())
+      continue;
     // Look for unnamed parameters.
     if (!Parm->getName().empty())
       continue;

clang-tools-extra/test/clang-tidy/readability-named-parameter.cpp

@@ -127,3 +127,7 @@ typedef decltype(nullptr) nullptr_t;
 }
 
 void f(std::nullptr_t) {}
+
+typedef void (F)(int);
+F f;
+void f(int x) {}