tests/test-fenv-env-6.c

   1 /* Test of controlling the floating-point environment.
   2    Copyright (C) 2023-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <bruno@clisp.org>, 2023.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include <fenv.h>
  23
  24 #include "fpe-trapping.h"
  25 #include "macros.h"
  26
  27 /* musl libc does not support floating-point exception trapping, even where
  28    the hardware supports it.  See
  29    <https://wiki.musl-libc.org/functional-differences-from-glibc.html>  */
  30 #if HAVE_FPE_TRAPPING && (!MUSL_LIBC || GNULIB_FEENABLEEXCEPT)
  31
  32 /* Test that feupdateenv(), unlike fesetenv(), can trigger traps.  */
  33
  34 int
  35 main ()
  36 {
  37   fenv_t env1;
  38
  39   /* Get to a known initial state.  */
  40   ASSERT (feclearexcept (FE_ALL_EXCEPT) == 0);
  41
  42   /* Enable trapping on FE_INVALID.  */
  43   if (sigfpe_on_invalid () < 0)
  44     {
  45       fputs ("Skipping test: trapping floating-point exceptions are not supported on this machine.\n", stderr);
  46       return 77;
  47     }
  48
  49   /* Save the current environment in env1.  */
  50   ASSERT (fegetenv (&env1) == 0);
  51
  52   /* Go back to the default environment.  */
  53   ASSERT (fesetenv (FE_DFL_ENV) == 0);
  54
  55   /* Modify the current environment.  */
  56   ASSERT (feraiseexcept (FE_INVALID) == 0);
  57
  58   /* Go back to env1.
  59      Since the exceptions flag FE_INVALID is currently set, and since
  60      env1 has trapping on FE_INVALID enabled, this should trap. */
  61   ASSERT (feupdateenv (&env1) == 0);
  62
  63   return test_exit_status;
  64 }
  65
  66 #else
  67
  68 int
  69 main ()
  70 {
  71   fputs ("Skipping test: feenableexcept not available\n", stderr);
  72   return 77;
  73 }
  74
  75 #endif