[preproc]
#if 1
pass
#endif

[preproc]
#if 1
pass

[preproc]
pass
#if 0
fail

[preproc]
#if 1
pass
#else
fail
#endif

[preproc]
#if 0
fail
#else
pass
#endif

[preproc]
#if 0
fail
#else
pass

[preproc]
#if 0
fail
#elif 1
pass
#else
fail
#endif

[preproc]
#if 1
pass
#elif 1
fail
#else
fail
#endif

[preproc]
#if 0
fail
#elif 0
fail
#else
pass
#endif

[preproc]
#if 0
#if 1
fail
#endif
#else
#if 0
fail
#else
pass
#endif
#endif

[preproc]
#if 0
fail
#endif
pass

[preproc]
#endif
pass

[preproc]
/* The #elif is effectively ignored here. */
#if 0
fail
#else
pass
#elif 0
#endif

[preproc]
#if 0
fail
#else
#elif 0
pass
#endif

[preproc]
/* Similarly, the second #else is effectively ignored here. */
#if 0
fail
#else
pass
#else
#endif

[preproc]
/* Similarly, the second #else is effectively ignored here. */
#if 0
fail
#else
#else
pass
#endif

[preproc]
#if 0
#define KEY fail
#else
#define KEY pass
#endif
KEY