[clang-tidy] add cert's VariadicFunctionDefCheck as cppcoreguidelines-pro-type-vararg-def

[mgehre]

Summary

Import the cert check for variadic function definitions into
cppcoreguidelines module to check part of
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-type8-avoid-reading-from-varargs-or-passing-vararg-arguments-prefer-variadic-template-parameters-instead

[aaron.ballman]

LGTM! (If you haven't already gotten commit privileges, now would be a good time to get them -- I will be out of town for two weeks starting Saturday, and alexfh is also currently out of town.)

~Aaron

[mgehre]

I have commit privileges :-)

clang-tidy/cppcoreguidelines/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS support)
 
 add_clang_library(clangTidyCppCoreGuidelinesModule
   CppCoreGuidelinesTidyModule.cpp
   ProBoundsPointerArithmeticCheck.cpp
   ProTypeConstCastCheck.cpp
   ProTypeReinterpretCastCheck.cpp
   ProTypeStaticCastDowncastCheck.cpp
 
   LINK_LIBS
   clangAST
   clangASTMatchers
   clangBasic
   clangLex
   clangTidy
+  clangTidyCERTModule
   clangTidyMiscModule
   clangTidyUtils
   clangTooling
   )

clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp

 //===--- CppCoreGuidelinesModule.cpp - clang-tidy -------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "../ClangTidy.h"
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
+#include "../cert/VariadicFunctionDefCheck.h"
 #include "../misc/AssignOperatorSignatureCheck.h"
 #include "ProBoundsPointerArithmeticCheck.h"
 #include "ProTypeConstCastCheck.h"
 #include "ProTypeReinterpretCastCheck.h"
 #include "ProTypeStaticCastDowncastCheck.h"
 
 namespace clang {
 namespace tidy {
 namespace cppcoreguidelines {
 
 /// A module containing checks of the C++ Core Guidelines
 class CppCoreGuidelinesModule : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<ProBoundsPointerArithmeticCheck>(
         "cppcoreguidelines-pro-bounds-pointer-arithmetic");
     CheckFactories.registerCheck<ProTypeConstCastCheck>(
         "cppcoreguidelines-pro-type-const-cast");
+    CheckFactories.registerCheck<VariadicFunctionDefCheck>(
+        "cppcoreguidelines-pro-type-vararg-def");
     CheckFactories.registerCheck<ProTypeReinterpretCastCheck>(
         "cppcoreguidelines-pro-type-reinterpret-cast");
     CheckFactories.registerCheck<ProTypeStaticCastDowncastCheck>(
         "cppcoreguidelines-pro-type-static-cast-downcast");
     CheckFactories.registerCheck<misc::AssignOperatorSignatureCheck>(
         "cppcoreguidelines-c-copy-assignment-signature");
   }
 };