xref: /aosp_15_r20/external/llvm-libc/test/src/fenv/feholdexcept_test.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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 "hdr/types/fenv_t.h"
10 #include "src/fenv/feholdexcept.h"
11 
12 #include "src/__support/FPUtil/FEnvImpl.h"
13 #include "src/__support/macros/properties/architectures.h"
14 #include "test/UnitTest/FEnvSafeTest.h"
15 #include "test/UnitTest/FPExceptMatcher.h"
16 #include "test/UnitTest/Test.h"
17 
18 #include "excepts.h"
19 
20 using LlvmLibcFEnvTest = LIBC_NAMESPACE::testing::FEnvSafeTest;
21 
TEST_F(LlvmLibcFEnvTest,RaiseAndCrash)22 TEST_F(LlvmLibcFEnvTest, RaiseAndCrash) {
23 #if defined(LIBC_TARGET_ARCH_IS_ANY_ARM) ||                                    \
24     defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
25   // Few Arm HW implementations do not trap exceptions. We skip this test
26   // completely on such HW.
27   //
28   // Whether HW supports trapping exceptions or not is deduced by enabling an
29   // exception and reading back to see if the exception got enabled. If the
30   // exception did not get enabled, then it means that the HW does not support
31   // trapping exceptions.
32   LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
33   LIBC_NAMESPACE::fputil::enable_except(FE_DIVBYZERO);
34   if (LIBC_NAMESPACE::fputil::get_except() == 0)
35     return;
36 #endif // Architectures where exception trapping is not supported
37 
38   int excepts[] = {FE_DIVBYZERO, FE_INVALID, FE_INEXACT, FE_OVERFLOW,
39                    FE_UNDERFLOW};
40 
41   for (int e : excepts) {
42     fenv_t env;
43     LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
44     LIBC_NAMESPACE::fputil::enable_except(e);
45     ASSERT_EQ(LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT), 0);
46     ASSERT_EQ(LIBC_NAMESPACE::feholdexcept(&env), 0);
47     // feholdexcept should disable all excepts so raising an exception
48     // should not crash/invoke the exception handler.
49     ASSERT_EQ(LIBC_NAMESPACE::fputil::raise_except(e), 0);
50 
51     ASSERT_RAISES_FP_EXCEPT([=] {
52       // When we put back the saved env, which has the exception enabled, it
53       // should crash with SIGFPE. Note that we set the old environment
54       // back inside this closure because in some test frameworks like Fuchsia's
55       // zxtest, this test translates to a death test in which this closure is
56       // run in a different thread. So, we set the old environment inside
57       // this closure so that the exception gets enabled for the thread running
58       // this closure.
59       LIBC_NAMESPACE::fputil::set_env(&env);
60       LIBC_NAMESPACE::fputil::raise_except(e);
61     });
62 
63     // Cleanup
64     LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
65     ASSERT_EQ(LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT), 0);
66   }
67 }
68