llvm-project/clang-tools-extra/test/clang-tidy/checkers/cert-variadic-function-def.cpp

// RUN: %check_clang_tidy %s cert-dcl50-cpp %t

// Variadic function definitions are diagnosed.
void f1(int, ...) {}
// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: do not define a C-style variadic function; consider using a function parameter pack or currying instead [cert-dcl50-cpp]

// Variadic function *declarations* are not diagnosed.
void f2(int, ...); // ok

// Function parameter packs are good, however.
template <typename Arg, typename... Ts>
void f3(Arg F, Ts... Rest) {}

struct S {
  void f(int, ...); // ok
  void f1(int, ...) {}
  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: do not define a C-style variadic function; consider using a function parameter pack or currying instead
};

// Function definitions that are extern "C" are good.
extern "C" void f4(int, ...) {} // ok
extern "C" {
  void f5(int, ...) {} // ok
}