llvm-project/clang/test/Lexer/preamble.c

// Preamble detection test: see below for comments and test commands.
//
#include <blah>
#ifndef FOO
#else
#ifdef BAR
#elif WIBBLE
#endif
#pragma unknown
#endif
#ifdef WIBBLE
#include "honk"
#else
int foo();
#endif

// This test checks for detection of the preamble of a file, which
// includes all of the starting comments and #includes. Note that any
// changes to the preamble part of this file must be mirrored in
// Inputs/preamble.txt, since we diff against it.

// RUN: %clang_cc1 -print-preamble %s > %t
// RUN: echo END. >> %t
// RUN: FileCheck < %t %s
// XFAIL: win32

// CHECK: // Preamble detection test: see below for comments and test commands.
// CHECK-NEXT: //
// CHECK-NEXT: #include <blah>
// CHECK-NEXT: #ifndef FOO
// CHECK-NEXT: #else
// CHECK-NEXT: #ifdef BAR
// CHECK-NEXT: #elif WIBBLE
// CHECK-NEXT: #endif
// CHECK-NEXT: #pragma unknown
// CHECK-NEXT: #endif
// CHECK-NEXT: END.