llvm-project/clang/test/PCH/attrs.c

// Test this without pch.
// RUN: %clang_cc1 -include %s -fsyntax-only -verify %s

// Test with pch.
// RUN: %clang_cc1 -emit-pch -o %t %s
// RUN: %clang_cc1 -include-pch %t -fsyntax-only -verify %s 

#ifndef HEADER
#define HEADER

int f(int) __attribute__((visibility("default"), overloadable)); // expected-note{{previous overload}}

#else

double f(double); // expected-error{{overloadable}}

#endif