1 //===-- Unittests for feraiseexcept 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/feclearexcept.h"
10 #include "src/fenv/feraiseexcept.h"
11 #include "src/fenv/fetestexcept.h"
12
13 #include "src/__support/FPUtil/FEnvImpl.h"
14 #include "src/__support/architectures.h"
15 #include "utils/UnitTest/FPExceptMatcher.h"
16 #include "utils/UnitTest/Test.h"
17
18 #include <fenv.h>
19 #include <signal.h>
20
21 // This test enables an exception and verifies that raising that exception
22 // triggers SIGFPE.
TEST(LlvmLibcExceptionStatusTest,RaiseAndCrash)23 TEST(LlvmLibcExceptionStatusTest, RaiseAndCrash) {
24 #if defined(LLVM_LIBC_ARCH_AARCH64)
25 // Few aarch64 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 __llvm_libc::fputil::disable_except(FE_ALL_EXCEPT);
33 __llvm_libc::fputil::enable_except(FE_DIVBYZERO);
34 if (__llvm_libc::fputil::get_except() == 0)
35 return;
36 #endif // defined(LLVM_LIBC_ARCH_AARCH64)
37
38 // TODO: Install a floating point exception handler and verify that the
39 // the expected exception was raised. One will have to longjmp back from
40 // that exception handler, so such a testing can be done after we have
41 // longjmp implemented.
42
43 int excepts[] = {FE_DIVBYZERO, FE_INVALID, FE_INEXACT, FE_OVERFLOW,
44 FE_UNDERFLOW};
45
46 // We '|' the individual exception flags instead of using FE_ALL_EXCEPT
47 // as it can include non-standard extensions. Note that we should be able
48 // to compile this file with headers from other libcs as well.
49 constexpr int ALL_EXCEPTS =
50 FE_DIVBYZERO | FE_INVALID | FE_INEXACT | FE_OVERFLOW | FE_UNDERFLOW;
51
52 for (int e : excepts) {
53 __llvm_libc::fputil::disable_except(FE_ALL_EXCEPT);
54 __llvm_libc::fputil::enable_except(e);
55 ASSERT_EQ(__llvm_libc::feclearexcept(FE_ALL_EXCEPT), 0);
56 // Raising all exceptions except |e| should not call the
57 // SIGFPE handler. They should set the exception flag though,
58 // so we verify that. Since other exceptions like FE_DIVBYZERO
59 // can raise FE_INEXACT as well, we don't verify the other
60 // exception flags when FE_INEXACT is enabled.
61 if (e != FE_INEXACT) {
62 int others = ALL_EXCEPTS & ~e;
63 ASSERT_EQ(__llvm_libc::feraiseexcept(others), 0);
64 ASSERT_EQ(__llvm_libc::fetestexcept(others), others);
65 }
66
67 ASSERT_RAISES_FP_EXCEPT([=] {
68 // In test frameworks like Fuchsia's zxtest, this translates to
69 // a death test which runs this closure in a different thread. So,
70 // we enable the exception again inside this closure so that the
71 // exception gets enabled for the thread running this closure.
72 __llvm_libc::fputil::enable_except(e);
73 __llvm_libc::feraiseexcept(e);
74 });
75
76 // Cleanup.
77 __llvm_libc::fputil::disable_except(FE_ALL_EXCEPT);
78 ASSERT_EQ(__llvm_libc::feclearexcept(FE_ALL_EXCEPT), 0);
79 }
80 }
81