llvm-project/clang/test/SemaCXX/nonnull.cpp

// RUN: %clang_cc1 -fsyntax-only -verify %s

template<int I>
struct TS {
  __attribute__((returns_nonnull))
  void *value_dependent(void) {
    return I; // no-warning
  }

  __attribute__((returns_nonnull))
  void *value_independent(void) {
    return 0; // expected-warning {{null returned from function that requires a non-null return value}}
  }
};

namespace Template {
  template<typename T> __attribute__((nonnull)) void f(T t);
  void g() { f((void*)0); } // expected-warning {{null passed to a callee that requires a non-null argument}}
  void h() { f(0); }
}