gcc/testsuite/gcc.dg/no-math-errno-4.c

/* Test __NO_MATH_ERRNO__ is defined and undefined by pragmas.  */
/* { dg-do compile } */
/* { dg-options "-fmath-errno" } */

#ifdef __NO_MATH_ERRNO__
#error "__NO_MATH_ERRNO__ defined"
#endif

#pragma GCC optimize "-fno-math-errno"
#ifndef __NO_MATH_ERRNO__
#error "__NO_MATH_ERRNO__ not defined"
#endif

#pragma GCC optimize "-fmath-errno"
#ifdef __NO_MATH_ERRNO__
#error "__NO_MATH_ERRNO__ defined"
#endif