libc/test/src/fenv/feholdexcept_test.cpp

   1 //===-- Unittests for feholdexcept with exceptions enabled ----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/fenv/feholdexcept.h"
  10
  11 #include "src/__support/FPUtil/FEnvImpl.h"
  12 #include "src/__support/macros/properties/architectures.h"
  13 #include "test/UnitTest/FPExceptMatcher.h"
  14 #include "test/UnitTest/Test.h"
  15
  16 #include <fenv.h>
  17
  18 TEST(LlvmLibcFEnvTest, RaiseAndCrash) {
  19 #if defined(LIBC_TARGET_ARCH_IS_ANY_ARM) ||                                    \
  20     defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
  21   // Few Arm HW implementations do not trap exceptions. We skip this test
  22   // completely on such HW.
  23   //
  24   // Whether HW supports trapping exceptions or not is deduced by enabling an
  25   // exception and reading back to see if the exception got enabled. If the
  26   // exception did not get enabled, then it means that the HW does not support
  27   // trapping exceptions.
  28   LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
  29   LIBC_NAMESPACE::fputil::enable_except(FE_DIVBYZERO);
  30   if (LIBC_NAMESPACE::fputil::get_except() == 0)
  31     return;
  32 #endif // Architectures where exception trapping is not supported
  33
  34   int excepts[] = {FE_DIVBYZERO, FE_INVALID, FE_INEXACT, FE_OVERFLOW,
  35                    FE_UNDERFLOW};
  36
  37   for (int e : excepts) {
  38     fenv_t env;
  39     LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
  40     LIBC_NAMESPACE::fputil::enable_except(e);
  41     ASSERT_EQ(LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT), 0);
  42     ASSERT_EQ(LIBC_NAMESPACE::feholdexcept(&env), 0);
  43     // feholdexcept should disable all excepts so raising an exception
  44     // should not crash/invoke the exception handler.
  45     ASSERT_EQ(LIBC_NAMESPACE::fputil::raise_except(e), 0);
  46
  47     ASSERT_RAISES_FP_EXCEPT([=] {
  48       // When we put back the saved env, which has the exception enabled, it
  49       // should crash with SIGFPE. Note that we set the old environment
  50       // back inside this closure because in some test frameworks like Fuchsia's
  51       // zxtest, this test translates to a death test in which this closure is
  52       // run in a different thread. So, we set the old environment inside
  53       // this closure so that the exception gets enabled for the thread running
  54       // this closure.
  55       LIBC_NAMESPACE::fputil::set_env(&env);
  56       LIBC_NAMESPACE::fputil::raise_except(e);
  57     });
  58
  59     // Cleanup
  60     LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
  61     ASSERT_EQ(LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT), 0);
  62   }
  63 }